UNIVERSITY OF ILLINOIS BULLETIN 

Issued Weekly 

Vol. XVII January 19, 1920 No. 21 

Entered aa second-class matter December 11, 1912, at the post office at Urbana. Illinois, under the act ot August 
24, 1912. Acceptance for mailing at the special rate of postage provided for in section 1103 
Act of October 3, 1917, authorized July 31, 1918] 


BITUMINOUS COAL STORAGE 

PRACTICE 

BY 

H. H. STOEK 
C. W. HIPPARD 
W. D. LANGTRY 



BULLETIN No. 110 

ENGINEERING EXPERIMENT STATION 

Published by the University op Illinois, Urbana 


Price: Ninety Cents 
European Agent 
Chapman & Hall, Ltd., London 

















T HE Engineering Experiment Station was established by act of 
the Board of Trustees, December 8, 1903. It is the purpose 
of the Station to carry on investigations along various lines of 
engineering and to study problems of importance to professional engi¬ 
neers and to the manufacturing, railway, mining, constructional, and 
industrial interests of the State. 

The control of the Engineering Experiment Station is vested in 
the heads of the several departments of the College of Engineering. 
These constitute the Station Staff and, with the Director, determine 
the character of the investigations to be undertaken. The work is 
carried on under the supervision of the Staff, sometimes by research 
fellows as graduate work, sometimes by members of the instructional 
staff of the College of Engineering, but more frequently by investiga¬ 
tors belonging to the Station corps. 

The results of these investigations are published in the form of 
bulletins, which record mostly the experiments of the Station’s own 
staff of investigators. There will also be issued from time to time, in 
the form of circulars, compilations giving the results of the experi¬ 
ments of engineers, industrial works, technical institutions, and gov¬ 
ernmental testing departments. 

The volume and number at the top of the front cover page are 
merely arbitrary numbers and refer to the general publications of 
the University of Illinois: either above the title or below the seal is given 
the number of the Engineering Experiment Station bulletin or circular 
which should be used in referring to these publications. 

For copies of bulletins, circulars, or other information address the 

Engineering Experiment Station, 
Urbana, Illinois. 


UNIVERSITY OF ILLINOIS 
ENGINEERING EXPERIMENT STATION 


Bulletin No. 116 


January, 1920 


BITUMINOUS GOAL STORAGE 


PRACTICE 


BY a 3 

/A> 

H. H. STOEK 

ti 

PROFESSOR OF MINING ENGINEERING 

C. W. HIPPARD 

i 

RESEARCH GRADUATE ASSISTANT 

W. D. LANGTRY 

PRESIDENT, COMMERCIAL TESTING AND ENGINEERING COMPANY 


* 


* '» 


ENGINEERING EXPERIMENT STATION 

Published by the University of Illinois, Urbana 












CONTENTS 


PAGE 

I. Introduction.11 

1. Interest in Storage of Coal.■ 11 

2. Conditions under which Coal Was Stored . . . . 11 

3. Sources of Information.12 

II. Summary of Conclusions.14 

4. Preliminary Considerations.14 

5. Preparation of Place of Storage.14 

6. Time of Year for Storage.15 

7. Kinds of Coal which May Be Safely Stored . . . .15 

8. Sulphur in Coal.16 

9. Method of Piling.16 

10. Moisture.17 

11. Inspection and Precautions.18 

III. Experience in the Storage of Coal during 1918-1919 . . 21 

12. Introduction.21 

13. Kinds of Coal that Can Be Stored.22 

14. Sizes of Coal that Can Be Stored.23 

15. Effect of Depth of the Pile.26 

16. Effect of Quantity of Coal in Storage.28 

17. Effect of Methods of Piling.28 

18. Causes of Fires.30 

19. Extent of Fires when Discovered.30 

20. Danger Temperatures in Coal Piles.31 

21. Detection of Coal Pile Fires.32 

22. Appliances for Reading Temperatures.37 

Thermometers.37 

Thermostats.37 

Recording Thermometers.38 

The Zeleny Thermometer.38 

Pyrometers.43 

Thermocouples.43 

Potentiometers.43 


23. Time when Fire Was Noted..46 


3 


























4 


CONTENTS (CONTINUED) 


24. Reducing Temperature and Extinguishing Fires in 

Coal Piles.47 

Moving the Coal.48 

Use of Water.48 

Use of Carbon Dioxide and Bicarbonate of Soda . 56 

Ventilation of Storage Piles.58 

Summary of Methods of Fighting Fires ... 60 

25. Damage to Propert}^ and Loss of Coal from Fires . . 60 

26. A Study of Fires in Coal Piles in Chicago during 1918 61 

Class 1. Fires Due Partially, if not Wholly, to 


Outside Sources of Heat.62 

Class 2. Combustion Aided by Foreign Material 
in the Coal.69 


Class 3. Fires Due to no Apparent Cause except 
the Kind of Coal or the Method of Piling . . 77 

27. Summary of Data from all Types of Chicago Fires . 79 


1V. Effects of Storage upon the Properties of Coal ... 83 

V. Storage Systems.86 

28. Hand and Truck Storage.86 

29. Pile Storage.87 

30. Trestle Storage.88 

31. Drag-Line Bucket Storage.93 

32. Silo Type of Storage Pockets.94 

Plant Expenses for One Month.96 

33. Portable and Semi-Portable Conveyors.101 

District of Columbia Storage Yard.108 

Erie Railroad Storage Plant.116 

34. Monorail System.118 

35. Cableway System.121 

36. Automatic Dump Car Storage.122 

37. Cristobal and Balboa Coaling Stations.122 

38. Suction Conveyor.127 

39. Mine Storage. 127 

40. Underwater Storage. 131 

Duquesne Light Company Storage Plant . . .131 

Underwater Pit of the Standard Oil Company, 
i Whiting, Indiana.132 























CONTENTS (CONTINUED) 


Appendix I . .135 

Questionnaire A .135 

Questionnaire B .135 

Data Sheet.130 

Appendix II .138 

Railway Administration Storage Circular.138 

The Storage of Coal . ..• . . . . 138 

Why Railroads and Other Consumers Should Store Coal . 138 

How to Store Coal . ‘.139 

Method ol* Unloading. 140 

Appendix III.142 

Space Occupied by Coal.142 











LIST OF FIGURES 


NO. 

1 . 

o 

fcj* 

3 . 

4 . 

5 . 

6 . 

7 . 

8 . 
9 . 

10 . 

11 . 

12 . 


13 . 

14 . 


15 . 

16 . 

17 . 

18 . 

19 . 

20 . 
21 . 
22 . 


23 . 

24 . 

25 . 

26 . 


PAGE 

Pile of Screenings with Temperature Tubes, Closed at Upper Ends by- 

Wooden Plugs.33 

Maximum Temperature Thermometer — Armored Type.37 

Recording Thermometer — Long Distance Type. 39 

Indicating Thermometer — Long Distance Type.39 

Zeleny Thermometer System -— Reading Instrument and Switch Board . 40 

Indicating Pyrometer — Millivoltmeter Type.40 

Indicating Pyrometer with Alarm Attachment.41 

Indicating Pyrometer — Potentiometer Type.41 

Base Metal Thermocouples for Pyrometers.42 

Plan and Section of Coal Pile Showing Arrangement of Receptacles for 
Pyrometers.44 

Temperature Record Blank Used by Chicago Great Western Railroad . 45 

Graph Showing Length of Time Coal Was in Storage when Fire Was 
Discovered (Questionnaire A) .40 

Graph Showing Length of Time Coal Was in Storage when Fire Was 
Discovered (Questionnaire B) .47 

Sprinkler System Used by Aurora, Elgin, and Chicago Railroad Com¬ 
pany, Batavia, Illinois.51 

Graph Showing Length of Time Coal Was in Storage when Fire Was 

Discovered (Chicago Coal Pile Fires, Class 1).03 

Coal Piled around Hot Water Tank.05 


Coal Piled about Sheet Iron Smoke Pipe.05 

Hot Steam Pipes about which Coal Was Piled, Causing Fire .... 00 

Coal Piled in Contact with Brick Wall of Furnace (Coal Has Been 
Partially Removed).00 

Coal Piled in Contact with Brick Wall of Furnace (Coal Has Been 
Partially Removed).07 

Coal Piled around Base of Chimney (Coal Has Been Partially Re¬ 
moved) .07 

Graph Showing Length of Time Coal Was in Storage when Fire Was 
Discovered (Chicago Coal Pile Fires, Class 2).70 

Fire Starting in Coal Pile around Embedded Wooden Beam .... 08 

Fire Starting in Coal Pile around Timbers of Trestle.08 

View of Coal Pile Showing Timber Retaining Wall Anchored into Coal 
Pile by Wooden Supports.71 

Partially Burned Wooden Horse Removed from Coal Pile.71 


6 

















LIST OF FIGURES (CONTINUED) 

NO 

27. Bracing Timbers Embedded in Coal Pile around which Fire Started . 

28. Wooden Fence Partially Destroyed by Fire in Coal Pile, Apparently Due 

to Contact of Coal with Timbers of Fence. 

29. View of Pile of Screenings with Horizontal Wooden Vents (Indicated by 

Arrows) near which Fire Developed. 

30. View of Coal Pile, with Vertical Wooden Vents (Indicated by Arrows) 

near which Fire Developed. 

31. Wood and Rubbish in Coal Pile around which Fire Started .... 

32. View of Coal Pile Ventilated with Iron Pipes which Acted as Flues; 

Fire Occurred . 

33. Graph Showing Length of Time Coal Was in Storage when Fire Was Dis¬ 

covered (Chicago Coal Pile Fires, Class 3). 

34. Graph Showing Length of Time Coal Was in Storage when Fire Was Dis¬ 

covered (All Classes of Chicago Coal Pile Fires). 

35. Graph Showing Relation between Length of Time in Storage and Total 

Number of Fires (All Classes of Chicago Coal Pile Fires) 

36. Railroad Coal Storage Pile at Enid, Oklahoma. 

37. Plan and Section Illustrating Standard Coal Storage System of Missouri 

Pacific Railroad . 

38. Ditcher Reclaiming Coal. 

39. Ditcher Reclaiming Coal. 

40. Cooling Duct under Pile. 

41. Plan and Section Illustrating Standard Coal Storage System of the New 

York, New Haven, and Hartford Railroad (Tonnage Given per 
Linear Foot).'. 

42. Drag-Line Coal Storage and Coal Handling Plant of Southern Railway 

at Air Line Junction, Virginia. 

43. Plan and Section of Coal Storage and Coal Handling Plant of Southern 

Railway at Air Line Junction, Virginia. 

44. Wooden Stave Silo Coal Storage Plant. 

45. Wooden Stave Silo Coal Storage Plant, Arranged for Bottom Discharge 

46. Side Elevation, Plan, and Section of Coal Storage Plant of American 

Hominy Company, Indianapolis, Indiana. 

47. Circular Method of Piling Coal, Using Both Portable and Semi-Portable 

Conveyors. 

48. Circular Method of Piling Coal Using Both Portable and Semi-Portable 

Conveyors — Plan and Section. 

49. Coal Storage Plant Using Fixed and Portable Conveyors at Mooseheart, 

Illinois. 

50. Coal Storage Plant Using Fixed and Portable Conveyors at Mooseheart, 

Illinois. 


7 

PAGE 

72 

72 

75 

75 

76 

76 

79 

81 

82 

91 

89 

91 

92 

90 

90 

92 

93 
97 
97 

100 

105 

103 

105 

106 




















8 


LIST OF FIGURES (CONTINUED) 


PAGE 


NO. 

51. View of Recent Addition to Mooseheart Plant, Showing Four Conveyors 

in Operation.10(3 

52. Plan and Sectional Views Illustrating Methods of Storing from and Re¬ 

claiming into Railroad Cars with Portable Conveyors.107 

53. Portable Conveyor Supported by Cable.107 

54. Portable Conveyor Supported by Overhead Trolley.Ill 

55. Government Coal Storage Plant, Washington, D. C. (Stuart System) . 109 

56. Surface Conveyor, Government Coal Storage Plant, Washington, D. C. . 112 

57. Stacker, Government Coal Storage Plant, Washington, D. C.112 

58. Distributing Bins and Office, Government Coal Storage Plant, Wash¬ 

ington, D. C.113 

59. Plan of Coal Storage Plant of the Erie Railroad, Buffalo, New York . .117 

60. View of Coal Storage Plant of the Erie Railroad, Buffalo, New York, 

Showing Conveyor No. 2 and Stacker Delivering to Conveyor No. 3 . 119 

61. View of Coal Storage Plant of the Erie Railroad, Buffalo, New York, 

Showing Loader at End of Conveyor No. 2.119 

62. Godfrey Conveyor System for Storing and Handling Coal.118 

63. Monorail System for Storing and Reclaiming Coal.120 

64. Cableway System for Handling Coal—-Both End Towers Fixed . . 121 

65. Cableway System for Handling Coal — Both End Towers Movable . .121 

66. Cableway System for Handling-Coal — One End Tower Fixed, the Other 

Movable.122 

67. Coal Storage Plant of the Karm Terminal Company, Bridgeport, Con¬ 

necticut .123 

68. Cristobal Coaling Station, Panama Canal.125 

69. Balboa Coaling Station, Panama Canal.126 

70. Suction Conveyor Coal Storage Plant of the Pierce-Arrow Motor Car 

Company, Buffalo, New York.128 

71. Storage System Used by the Montevallo Mining Company, Aldrich, Ala¬ 

bama .129 

72. Underwater Coal Storage Plant of the Standard Oil Company, Whiting, 

Indiana (100 000 Tons - Capacity).129 

73. Underwater Coal Storage Plant of the Standard Oil Company, Whiting, 

Indiana — Sectional View and Details.133 

74. Method of Building Pyramidal Pile in Layers.140 

75. Dimensions for Determining Volume and Weight of Coal Piles . . .148 















LIST OF TABLES 


NO. PAGK 

1. Geographical Sources of Supply of Stored Coal.22 

2. Effect on Spontaneous Combustion of Size of Coal (Questionnaire A) . 24 

3. Effect on Spontaneous Combustion of Size of Coal (Questionnaire B) . 24 

4. Results of Mixture of Sizes and Kinds of Coal.26 

5. Effect on Spontaneous Combustion of Depth of Coal Pile.27 

6. Effect on Spontaneous Combustion of Quantity of Coal in Storage . . 28 

7. Effect on Spontaneous Combustion of Method of Piling Coal .... 29 

8. Causes of Fire.30 

9. Extent to which Heating Had Progressed.30 

10. Temperature Observed in Storage Piles.31 

11. Methods of Fighting Fires. 60 

12. Losses of Coal Due to Fires.60 

13. Classification of Fires in Chicago Coal Piles.62 

14. Fires Apparently Due to Foreign Material in Coal Piles.69 

15. Relation between Size of Coal and Number of Fires.77 

16. Relation between Segregation of Sizes in Piling and Number of Fires . 78 

17. Capacity of Portable Conveyors.102 

18. Weight of Bituminous Coal in Pounds per Cubic Foot by Districts . .142 

19. Weight of Bituminous Coal in Pounds per Cubic Foot by States . . . 143 

20. Weight per Cubic Foot of Coal as Given by Manufacturers . . . 144-145 

21. Cubic Feet per Ton of Coal.146 

22. Weight per Cubic Foot of Illinois and Indiana Coal.146-147 

23. Space Occupied by Bituminous Coal in Cubic Feet per Ton .... 147 

24. Space Occupied by Bituminous Coal in Cubic Feet per Ton .... 148 

25. Space Occupied by Anthracite Coal in Cubic Feet per Ton . . . .148 

26. Volume and Tonnage of Bituminous Coal Piles.149 























THE STORAGE OF BITUMINOUS COAL 


I. Introduction 

1. Interest in Storage of Coal .—One result of the coal shortage 
during the winter of 1917-1918 was to impress upon the general pub¬ 
lic, and particularly upon the Fuel Administration, the necessity of 
having a coal pile on which to draw in time of stress such as occurred 
during the winter of 1918. 

Upon the recommendation of the Illinois Fuel Administration, a 
systematic campaign was instituted by the United States Fuel Ad¬ 
ministration in Washington, urging people to store coal. The con¬ 
clusions and recommendations of the Engineering Experiment Station 
Circular No. 6 # were reprinted in condensed form and given wide 
publicity by several State Fuel Administrations, by the Retail Coal 
Dealers Association of Illinois and Wisconsin, and by the National 
Board of Fire Underwriters. As a result of this campaign, it is safe 
to say that never before had so much attention been paid to the storage 
of coal as was the case in the spring and summer of 1918. 

During the past year unusual attention has also been given to 
the subject of coal storage in England and in Canada and the con¬ 
clusions which were reached in these countries, and which will be 
referred to later in fuller detail, agree very closely with the experience 
in the United States. 

Details as to the amounts of coal in storage at different periods 
and the methods used to stimulate storage will be found in the re¬ 
ports of the Fuel Administration. 

2. Conditions under which Coal Was Stored .—The present bulle¬ 
tin aims to supplement Circular No. 6 by presenting information 
secured in a further study of the shortage of coal under conditions 
somewhat different from those that existed prior to the publication 
of Circular No. 6 in the early part of 1918. These new conditions 
were: 

(1) On account of the pooling of coals from a number 

of different districts and the zoning system of distribution 

* “The Storage of Bituminous Coal,” by H. H. Stoek. • Univ. of Ill., Eng. Exp. Sta. 
Circular No. 6, 1918. 


11 




12 


ILLINOIS ENGINEERING EXPERIMENT STATION 


under the United States Fuel Administration during 1918, 
many were compelled to buy a different coal from that to 
which they had been accustomed in the past. 

(2) It was often impossible to secure continuous ship¬ 
ments of the same coal; therefore it was frequently necessary 
to store a mixture of coals. 

(3) Owing to the great demand for a maximum output 
under war conditions, less care was given to the preparation 
of the coal, with regard both to its sizing and to the separa¬ 
tion of impurities; consequently much coal was stored that 
was not suitable for the purpose. 

(4) Owing to the campaign for storing coal carried 
on mainly by government agencies, undoubtedly much more 
coal was stored than under ordinary conditions, and much 
of this was stored by people without any previous experience 
in the storing of coal. 

In some cases, therefore, the results of storage during 1918 were 
discouraging to those who had no previous experience in storing coal. 
One purpose of this further study of the subject was to find out the 
experience of those who stored under these unusual conditions and, 
if necessary, to modify the conclusions and suggestions contained in 
Circular No. 6. 

.« 

3. Sources of Information .—The data for the present bulletin 
were obtained: 

(1) From a questionnaire sent to the same individuals 
or companies upon whose experience the conclusions pub¬ 
lished in Circular No. 6 were based. These included about 
two hundred individuals, manufacturing concerns, railroads, 
coke plants, etc., that had stored coal under widely differing 
conditions. 

(2) From a similar questionnaire which, through the 
cordial cooperation of Joseph Harrington, Administrative 
Engineer of the Illinois Fuel Administration, was sent to 
about eighteen thousand power plants in Illinois. From this 
questionnaire about three hundred answers were received. 

(3) From a careful study of fires in coal piles in 
Chicago. This study was made by W. D. Langtry in con- 


BITUMINOUS COAL STORAGE PRACTICE 


13 


nection with work begun under the Conservation Department 
of the United States Fuel Administration in Illinois. J. C. 
McDonald, chief of the Bureau of Fire Prevention and Pub¬ 
lic Safety of Chicago, for a period of six months beginning 
about May 1, 1918, reported daily all fires in coal piles in 
Chicago and either Mr. Langtry or Mr. IIippard, Research 
Assistant in Mining Engineering of the Engineering Experi¬ 
ment Station, investigated most of these fires and, in many 
cases, took photographs of them. 

(4) From investigations made by the authors of this 
bulletin of fires which occurred in Mattoon, Decatur, Rock 
Island, Moline, Davenport, Aurora, Champaign, Urbana, St. 
Louis, and Milwaukee. The fires in these cities had been 
reported either to the local fire departments or to the County 
Fuel Administrators who were most helpful by notifying the 
authors of coal in storage and of fires. The conditions 
under which fires occurred in these cities were similar to 
those under which fires occurred in Chicago. 

(5) From information furnished through the cordial 
cooperation of E. A. McAuliffe and the following super¬ 
visors of the Fuel Conservation Section of the United States 
Railroad Administration: E. P. Roesch, Robert Collett, 

B. R. Feeny, 11. C. Woodbridge, N. Clewer, J. W. Hardy, 
and L. R. Pyle. # S. W. Parr, Professor of Industrial 
Chemistry, University of Illinois, whose bulletins on spon¬ 
taneous combustion are well known, has been most helpful 
through suggestions and criticisms of the manuscripts. Mr. 
Hippard not only cooperated with Mr. Langtry in studying 
Chicago fires, but also compiled the data secured in connec¬ 
tion with these fires and the replies to the several question¬ 
naires. So many have cooperated in gathering information 
that it is impossible to give adequate credit to all by name. 

* See “Storage of Coal by Railroads during 1918,” by H. H. Stoek. Inter. Ry. 

Fuel Assoc. Proc., 1919. 



14 


ILLINOIS ENGINEERING EXPERIMENT STATION 


II. Summary of Conclusions 

It is believed that the following conclusions will be helpful to any 
one who expects to store coal. These conclusions and the evidence 
upon which they are based are discussed in detail in the subsequent 
pages of this bulletin. 

4. Preliminary Considerations .— 

(1) Storage of coal insures the consumer a regular 
supply of coal, assists in equalizing freight traffic on the 
railroads, and helps to stabilize the operation of coal mines. 

(2) The storage of coal should not be undertaken with¬ 
out a careful consideration of the practice of those who have 
stored coal successfully. 

(3) Before it is time to begin the actual storing a 
suitable place should be prepared and a policy outlined far 
enough in advance so that every one who will have to do with 
the storing can receive definite instructions and not mere 
suggestions. It is unwise to wait until the coal to be stored is 
on the track and then to dump it anywhere so as to release 
the cars promptly. When storing begins, the instructions 
should be carried out to the letter. Many failures in storing 
coal have been due, not to faulty instructions, but to the 
fact that the instructions have not been followed. 

5. Preparation of Place of Storage .—If possible a place should 
be chosen that is dry and well drained; if not drained naturally, 
drains should be provided about the storage pile, not underneath it, 
as a drain beneath a pile may produce an air current up through the 
pile and thus assist spontaneous combustion. 

Coal should not be dumped on ground covered with ashes or 
refuse of any kind, because often in addition to furnishing flues for 
the admission of air, such refuse contains combustible material; 
furthermore, the presence of such refuse will depreciate the value of 
the coal when it is reclaimed from storage. If possible, the ground 
should be cleared of vegetation and leveled off, so that the reclaiming 


BITUMINOUS COAL STORAGE PRACTICE 


15 


of the coal will be made as easy as possible and that, in reclaiming, 
dirt and refuse will not be taken up by the shovel or by other devices 
used. There is some justification for the objection of firemen to using 
coal that has been stored, because of the dirt and other refuse that 
has been mixed with the coal in taking it from the storage pile. A 
hard clay bottom thoroughly drained is desirable, if a concrete is too 
expensive. 

If possible, adequate space should be provided so that the coal 
can be moved, if heating occurs. Coal should not be piled around 
hot pipes, against a boiler, against hot walls, around a chimney, or 
in any place where it will be subjected to outside heat, because the 
liability to spontaneous combustion increases rapidly with a rise in 
temperature. Coal should not be stored above flues that will permit 
a current of air to enter the coal pile; hot air such as that from a 
sewer is particularly to be avoided. 

6. Time of Year for Storage .—In order best to equalize trans¬ 
portation facilities, to help stabilize mine operation, and sometimes 
to take advantage of lower prices, coal should be stored between the 
first of May and the first of September. However, as these are the 
hottest months of the year, special precautions should be taken both 
in storing and in watching the coal after it is placed in storage. Coal 
is a poor conductor of heat and if coal that is already at a high 
temperature is covered by other coal, it retains the heat and is much 
more liable to spontaneous combustion than coal that is stored at a 
lower temperature. 

7. Kinds of Coal which May Be Safely Stored .—It is probably 
true that all varieties of bituminous coal have been stored without 
fire resulting, and equally true that all varieties of coal have fired 
when stored. These facts do not mean that all coals store equally 
well, as there is undoubtedly a difference in coals in this respect. 
The kind of coal that is to be stored should be specified. Coals that 
are known to be particularly liable to spontaneous combustion should 
not be selected for storage if it is possible to avoid doing so. If there 
is no choice of coal to be had, greater precautions in piling and in 
watching storage piles will be necessary. 

The spontaneous combustion of coal is due largely to the oxida¬ 
tion of fine coal; consequently, the liability to spontaneous combustion 


16 


ILLINOIS ENGINEERING EXPERIMENT STATION 


in stored coal is greatly reduced and in many cases eliminated if dust 
and fine coal can be kept out of the pile. 

Hence, if possible, cleaned, screened coal of a uniform size should 
be chosen, the larger the lumps the better, so as to give the greater 
number of voids in the pile. Coal of one size is better than a mixture 
of sizes. 

Sized coal should not be stored upon a foundation of fine coal. 

The coal should be handled in such a way as to prevent break¬ 
age as much as possible. If there is a choice of coals for storage, 
the least friable should be chosen and the one in which there is the 
least fine material. 

While many varieties of mine-run coal cannot be stored safely 
under ordinary conditions because of the presence of fine coal and 
dust, such coal has been successfully stored in small, low piles. In 
storing mine-run coal, it should be piled uniformly so as to prevent 
segregation of.the sizes. 

As fine coal or slack is more liable to spontaneous combustion 
than clean sized coal, it should be very carefully watched in storage 
to detect evidence of heating. 

8. Sulphur in Coal .—Although experimentation has shown that 
the sulphur contained in coal in the form of pyrites is not the chief 
cause of spontaneous combustion as was formerly supposed, yet the 
oxidation of the sulphur in the coal not only produces heat but also 
assists in breaking up the lumps and thus increasing the amount of 
fine coal in the pile. Any considerable rise in temperature from 
either external or internal sources promotes the oxidation of the iron 
pyrites. This oxidation produces heat and thus increases the liability 
of the coal to spontaneous combustion. It is wise to select low sulphur 
coals for storage if obtainable, but it must not be taken for granted 
that a low sulphur coal will necessarily store well. 

9. Method of Piling .— 

(1) Coal should be so piled for storage that any part 

of the pile can be moved promptly if necessary. 

(2) Coal should be so piled that air may circulate 

freely through it and thus carry off any heat generated, or 

else so closely packed that air cannot enter the pile; i.e., under 


BITUMINOUS COAL STORAGE PRACTICE 


17 


water storage conditions should be approximated as nearly 
as possible. 

(3) Stratification or segregation of fine and lump coal 
should be avoided, since an open stratum of coarse lumps 
provides passage for air to reach the fine coal but not in 
sufficient quantity to keep down the temperature of the pile. 
Coal should be spread in horizontal layers and not dumped in 
conical piles, for in the latter case the fine coal stays in the 
center at the top of the pile and the lumps roll to the bottom. 

(4) The depth and area of storage piles will be deter¬ 
mined largely by the storage space available and the mechan¬ 
ical appliances to be used. Other conditions being equal, 
the deeper the pile and the greater its area the greater the 
difficulty in inspecting it, and in moving it quickly if neces¬ 
sary. Hence, a number of small piles, if practicable, are 
better than one large pile. Lack of space, however, usually 
prevents such spreading out of the coal. It is impossible 
to specify exact heights as so much depends upon the kind of 
coal and upon local conditions. # 

(5) The hazard of spontaneous combustion seems to 
be independent of whether the coal is piled in the open or 
under cover. 

10. Moisture .— The exact effect of moisture in connection with 
spontaneous combustion is not known, and, as shown in later pages, 
the evidence of laboratory experiments is contradictory. 

The repeated wetting and drying of coal seems to increase the 
tendency to spontaneous combustion. This may be due to the break¬ 
ing up of the coal which such alternate wetting and drying occasions, 
even if there is no chemical reaction between the water and the coal. 
It is not wise to put wet coal into a pile, or to store coal on a damp 
base if it can be avoided. After a rain or snowstorm a coal pile 
should be carefully inspected and watched. 


* The Railroad Administration lias suggested piling coal for railroad storage not over 
twelve to fifteen feet in height when the track is placed on top of the coal pile, and not. 
over twenty feet when a locomotive crane is used. 

The Home Insurance Company advises against piling in excess of twelve feet, or more 
than one thousand five hundred tons in any pile, and suggests trimming the piles so that 
no point in the interior is more than ten feet from an air cooled surface. These are wise 
precautions, but frequently impossible of application on account of lack of storage space. 



18 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Water is an effective agent in quenching fire in a coal pile only 
if it can be applied in sufficient quantities to extinguish the fire and 
to cool the mass. The water must be applied at the' source of the fire, 
for it can do little good if the stream is only played on the surface. 
To be sure that the water reaches the fire it is usually necessary to 
turn over the coal. 

It is advisable to have water and hose available for use in case 
of necessity, but water should be used carefully and only as a last 
resort after other means, such as moving the coal, have been tried 
to lower the temperature. An effort should be made to determine the 
seat of the heating and to remove the coal affected, which should be 
spread out on the ground and allowed to cool off in the air, if possible. 
Only in case of necessity should water be used to cool it. If coal is 
ablaze it is necessary to add water, which very often will so control 
the fire that the danger to surrounding buildings is reduced, and 
more time is allowed to move the coal. Coal that has once heated 
should preferably be used at once and not be returned to the pile. 

11. inspection and Precautions .—There should be an inspector 
at each storage pile who not only is competent to inspect the coal 
furnished but who also has authority to reject it if not according to 
specifications and to see that the storage instructions are carried out. 

Coal in storage should be inspected regularly and if the tempera¬ 
ture reaches 140 degrees, the pile should be very carefully watched. 
If the temperature continues to rise rapidly and reaches 150 to 160 
degrees, the coal should be moved as promptly as possible and the 
coal thus moved should be thoroughly cooled before being replaced 
in storage, or still better, it should be used at once. If the tempera¬ 
ture rises slowly the pile should be carefully watched, but it is not 
necessary to begin moving the coal at as low a temperature as when 
the rise is rapid, for the temperature may recede and the danger 
be past. 

Coal should be moved before it actually smokes. Such smoking is 
reported to begin at 180 degrees Falir., though there is no very 
definite information on this point. Steaming should not be confused 
with smoking, for steam is frequently seen coming from a pile and 
this does not necessarily indicate a danger point. Temperature tests of 
coal in storage should be made, if possible, and one should not depend 
on such indications of fire as odor or smoke coming from the coal. 


BITUMINOUS COAL STORAGE PRACTICE 


19 


for when the coal reaches this stage it is well along in the process of 
combustion. Every storage plan should give special attention to load¬ 
ing out the coal quickly and promptly, if necessary. 

Inflammable material, such as waste, paper, rags, wood, rosin, 
oil, and tar in a coal pile often form the starting point for a fire, 
and every effort should be made to keep such material from the coal 
as it is being placed in storage. Irregular admission of air into the 
coal pile around the legs of a trestle, through a porous bottom such 
as coarse cinders, or through cracks between boards, etc., should be 
avoided. 

It is very important that coal in storage should not be subject 
to such external sources of heat as steam pipes, because the sus¬ 
ceptibility of coal to spontaneous combustion increases rapidly as 
the temperature rises. 

The effect of ventilating of coal piles is a disputed point, but 
the weight of evidence in the United States seems to be against the 
practice. This may possibly be due to the fact that ventilation has 
been inadequately done. The imperfect ventilation generally 
attempted in the United States is certainly disadvantageous, though 
reports from Canadian practice favor ventilation. 

About 75 per cent of the coal pile fires studied have occurred 
within ninety days after the coal was placed in storage; hence par¬ 
ticular attention should be given to the pile during the first three 
months that it is in storage. The greater the area of the pile exposed 
to the air the more quickly will the danger be passed. 

Coal stored during the summer should, if possible, not be drawn 
on in the early fall, as is so often done, but kept for the time of con¬ 
gestion in railroad traffic, which usually occurs from December to 
March. 

Finally, safety in the storage of coal depends upon careful atten¬ 
tion to the details given in the foregoing conclusions, which represent 
the experience of a large number of those who have stored coal in 
amounts varying from a few tons up to hundreds of thousands of 
tons, and under widely different conditions. 

A storage plan must consider all of the conditions, and not only 
a part; for instance, clean, lump coal of a certain kind may be stored 
with perfect safety in high piles; while the same coal, run-of-mine 
or unscreened, may not be safety stored at all, or at least only in 
small piles. Lack of attention to details in storage or failure system- 


20 


ILLINOIS ENGINEERING EXPERIMENT STATION 


atically to inspect storage piles and to be ready for any emergency 
that may occur, may result in losses from tires. 

For such amounts as are required by the ordinary householder, 
namely, ten to twenty tons a year, it can be positively stated (a) 
that there is little or no danger of spontaneous combustion if the 
foregoing suggestions are followed and (b) that there is no appreci¬ 
able deterioration in the heating value. 

As the amount of coal stored increases, increased care must be 
taken in the method of storing and in watching the coal after storage. 


BITUMINOUS COAL STORAGE PRACTICE 


21 


III. Experience in the Storage op Coal during 1918-1919 
Data Secured by Questionnaires 

12. Introduction .—As was previously mentioned, an effort lias 
been made by means of questionnaires to secure information that 
would confirm, modify, or refute the conclusions upon the storage 
of coal as given in Circular No. 6. 

Questionnaire A (see Appendix I) was sent to those from whom 

the information was obtained that was used in the preparation of 

Circular No. 6. This list included about one hundred and seventy-five 

«/ 

individuals and companies who stored coal under widely different 
conditions and in greatly differing amounts, varying from the ordi¬ 
nary householder storing from ten to twenty tons, to such industries 
as the by-product coke companies, wholesale distributors of coal, 
large utilities companies, railroads, etc., storing as high as hundreds 
of thousands of tons. An effort was also made to include‘all varieties 
of storage; i. e., at the mines, by railroads, by large and small power 
plants, etc. 

Questionnaire B (see Appendix I) was sent to the power plants 
of the State through the courtesy of Joseph Harrington, Admin¬ 
istrative Engineer, United States Fuel Administration, Chicago. 

It is realized that data obtained by questionnaires are somewhat 
uncertain, because of the difficulty of having those who fill out the 
questionnaires understand fully just what is desired in answer to 
the questions, and also because the data furnished may be interpreted 
in a sense different from that intended by the one filling out the ques¬ 
tionnaire. However, it is probable that these difficulties are more 
than balanced by the much larger amount of material that can be 
gathered by the questionnaire method; by averaging a large number 
of answers these inaccuracies are minimized. As far as possible any 
ambiguity in the answers was cleared up by additional correspondence. 

The data for the fires in Chicago were secured in person by 
either Mr. Langtry or Mr. Hippard who had unusual opportunity 
for obtaining first-hand information concerning these fires. 

Tn tabulating and studying these data many variables must be 
considered, which are so interrelated that great care must be taken 
to avoid drawing erroneous conclusions from any one set of figures 


22 


ILLINOIS ENGINEERING EXPERIMENT STATION 


by failing to consider them in their proper relation to the other 
factors, even when these related factors cannot be expressed in the 
tabulated material. Therefore, general conclusions should not be 
drawn from isolated statements and tables. 

13. Kinds of Coal that Can Be Stored .—Table 1, giving a 
statement of fires by districts from which the coal was obtained, not 
only substantiates the conclusions published in Circular No. 6 that 


Table No. 1 

Geographical Sources of Supply of Stored Coal 


District 


Arkansas. 

Cape Breton. 

Colorado. 

Eastern Pool. 

Illinois: 

Christian-Macon Co. 

Danville.. 

Franklin Co. 

Longwall. 

Peoria. 

Saline. 

Springfield. 

Standard . 

District not known. 

Illinois and Indiana. 

Indiana: 

Clinton. 

Mercer Co. 

Northern. 

Pike. 

Terre Haute. 

No. 4 Vein. 

District not known. 

Iowa. 

Kentucky. 

Lake Ports Pool. 

Michigan, Bay Co. 

Ohio. 

Oklahoma.... 

Pennsylvania 

Anthracite. 

Bituminous. 

Red Lodge (Montana) sub-bit. 

Virginia. 

West Virginia. 


Questionnaire A 


Fired 


Totals. 


-d 

<d 


o 

£ 


73 

0) 

X 


31 


23 


Not 

Fired 


73 

CD 

X 

• I-* 

o 


73 

a; 

x 


28 


Total 


73 

<d 

X 


o 

£ 


1 

12 


2 

4 

4 

2 


10 


73 

<d 

X 


59 


33 


Questionnaire B 


Fired 


73 

as 

X 


o 


12 

1 

15 

5 

7 

2 

11 

7 

3 

1 

1 

1 


68 


73 

4 ) 

X 


Not 

Fired 


T otal 


73 

CD 

X 

• r-< 

fc-H 

& 

o 


73 

CD 

X 


73 

CD 

X 


O 

£ 


14 


30 

1 

88 

21 

9 

7 

26 

10 

19 

2 


222 


13 


42 

2 

103 

26 

16 

9 

37 

17 

22 

3 

1 

2 


.1 

1 


290 


73 


1 

2 

3 

2 


27 






















































































































BITUMINOUS COAL STORAGE PRACTICE 


23 • 

‘ ‘ most varieties of bituminous coal may be safely stored if of proper 
size and free from fine coal and dust,” but also suggests the even 
more general conclusions: that although practically every kind of 
bituminous coal has been stored without spontaneous combustion occur¬ 
ring, yet under certain conditions spontaneous combustion has oc¬ 
curred with practically every kind of coal stored . 

Table 1 also shows that the percentage of fires in piles of mixed 
coals is considerably greater than in piles of the same coals unmixed. 
Although no satisfactory explanation of the phenomenon has been 
offered, the opinion is very generally held that a mixture of two coals 
is more liable to spontaneous combustion than either one separately, 
and all the evidence gathered seems to support this opinion. 

The Commonwealth Edison Company of Chicago, which has been 
very successful in storing large amounts of coal, reports that between 
February 26 and April 14, 1918, it stored at the Fisk Street plant 
about 3000 tons of central Illinois coal, principally egg and lump 
from one particular mine and a small amount of coal of the same 
size from two other mines, one located in central and the other in 
southern Illinois, together with six cars of run-of-mine coal from 
the same mines. The ground was cleared of old coal before the new 
coal was stored. During the early part of August, 1919, the pile was 
found to be heating and a part was removed and used at once. 

Another phase of'the question concerns the placing of fresh coal 
upon coal that has been in storage for some time, and a number of 
fires have been cited as taking place at the junction of the fresh and 
the old coal soon after the fresh coal had been placed in storage. For 
several fires investigated by the writers there was no other apparent 
cause. No explanation of this has been offered, and it is a subject 
requiring further investigation. 

14. Sizes of Coal that Can Be Stored. —Tables 2 and 3 show 
that the fire hazard for piles of clean, sized coal is relatively small, 
compared with that for piles of screenings or mine-run, and that the 
size is hn important factor in connection with storage. Table 2 shows 
that 56 per cent of all the piles of mine-run fired, and that 85 per 
cent of the piles of screenings fired. Table 3 shows that 88 per cent 
of the fires occurred in mine-run or screenings. Of the 98 storage 
piles of mine-run about 23 per cent fired, while of the 86 storage piles 
of screenings, 51 per cent fired. Of the 132 storage piles of sized 
coal less than 7 per cent fired. 


24 


ILLINOIS ENGINEERING EXPERIMENT STATION 


These results appear conclusive enough to support the recom¬ 
mendation that screenings or mine-run should not be stored in large 
quantities excepting under water, but if it is necessary to store these 
sizes in any other way, they should be very carefully watched for 
evidences of heating and means provided for rapidly and promptly 
moving the coal if heating is detected. A mixture of sizes gives a 
pile much less void space and hence the heated air is less readily 
carried off. 

Table 2 


Effect on Spontaneous Combustion of Size of Coal 

Questionnaire A 


Size of Coai. 

Fired 

Not Fired 

Total 

No. 

Per Cent 
of Total 

Per Cent 
of Given 
Size 

No. 

Per Cent 
of Total 

Per Cent 
of Given 
Size 


Lump (over 1 x 4 in.). 

2 

4.44 

33.33 

4 

12.12 

66.67 

6 

Lump (% in. to 114 in.) .... 

3 

6.07 

42.86 

4 

12.12 

57.14 

7 

Egg . 

0 



1 

3.03 

100.00 

1 

Mine-run. 

*22 

48.89 

56.41 

17 

51.51 

43.59 

39 

Screenings. 

18 

40.00 

85.72 

3 

9.10 

14.28 

21 

Buck (anthracite). 

0 



1 

3.03 

100.00 

1 

Nut. .'..'. 

0 



1 

3.03 

100.00 

1 

No. 1 nut. 

0 



1 

3.03 

100.00 

1 

No. 4 nut. 

0 



1 

3.03 

100.00 

1 

Totals. 

45 

100.00 


33 

100.00 


78 


* Three of these piles were a mixture of mine-run and screenings in about equal proportions. 


Table 3 

Effect on Spontaneous Combustion of Size of Coal 


Questionnaire B 


Size of Coal 

Fired 


Not Fire< 

1 

Total 

No. 

Per Cent 
of Total 

Per Cent 
of Given 
Size 

No. 

Per Cent 
of Total 

Per Cent 
of Given 
Size 


Lump (2 in. or over). 

1 

1.32 

1 .96 

50 

20.83 

98.04 

51 

Lump ('$4 in., 1 in., 1)4 in. 

0 



5 

2 08 

100 00 


Egg. 

2 

2.63 

6.25 

30 

12.50 

93.75 

32 

Mine-run. 

23 

30.26 

23.45 

75 

31.25 

76.55 

98 

Screenings. 

44 

57.89 

51.16 

42 

17.50 

48.84 

86 

No. 1 and No. 2 nut. 

1 

1.32 

3.85 

25 

10.42 

96.15 

26 

No. 3 and No. 4 nut. 

5 

6.58 

27.80 

13 

5.42 

72.20 

18 

Totals. 

76 

100.00 


240 

100.00 


316 








led til e experience in England and 

John H. Anderson of Purfleet, England, saysf: 


t Trans. Inst, of Marine Engineers. June, 1918. 















































































BITUMINOUS COAL STORAGE PRACTICE 


25 


When the coal is at a low temperature this oxygen absorption is very little; 
therefore, there is not much heat generated, and in many cases this little heat 
escapes to the atmosphere just as fast as it is generated. This is generally the 
(ase with the larger coals or coals free from small dust when there is usually a 
path here and there sufficient to allow the heat to get through to the surface by 
natural means. 

On the other hand, heaps may be composed of small coal, which may be so 
dense that there will not be sufficient apertures or paths for the generated heat to 
escape; the consequence is that this heat gathers, thereby increasing the tem¬ 
perature of the coal, and incidentally, due to the increase of heat, it increases the 
rapidity and capacity for further oxygen absorption in a given time, thus giv¬ 
ing off more heat in a given time than when the heap was cooler. 

‘ ‘ It will be seen from this that if a heap has a tendency to rise in temperature 
steps must immediately be taken to arrest this, otherwise the increase of heat will 
be so rapid after a time that it will not be possible to cope with it unless drastic 
measures are taken, such as to turn over the heap, or as it has happened before, 
letting it burn itself out. 

I ‘ The liability of small coal to create spontaneous combustion is very pro¬ 
nounced, both from its size and also from it closing up the paths whereby the 
heat generated would otherwise escape freely to the atmosphere. I suggest that most 
of the oxidation is superficial and, therefore, if the smalls absorb more oxygen, 
they generate more heat in a given time than the larger coal, and therefore, small 
coal is more liable to fire than large coal, particularly if steps are not taken to 
let this heat out. This means that there is one safe height that must not be exceeded, 
but as there are other factors that must be taken into consideration at the same 
time, it would be almost impossible to fix this height for every heap. The height 
of pile can be increased above this safe height, providing means are taken to vent 
it. The more it is vented the higher the heap can be piled. Generally speaking, 
12 to 14 feet is about as high as one should deposit small sized coals; 9 to 12 feet 
for unwashed mixed coals; for slack a great deal depends upon the composition. 
Two heaps of slack were allowed to. rise 120 degrees before moving. These heaps 
gave considerable trouble at a height of 10 feet, but even when the height was 
reduced to 6 feet, there was a tendency to increase in temperature. My opinion 
of the cause of the trouble was bad washing of the material; thus after a shower, 
the shale-like material formed a plastic mass with the coal practically preventing 
any escape of heat. 

“As a rule, little trouble is experienced in the storage of large coal, but one 
must be careful even with this, for in event of fire great difficulty will be ex¬ 
perienced in putting it out owing to the ready access of oxygen for supporting 
combustion. Care should be taken not to make any smalls when depositing this 
coal, and if possible the coal should be selected that will weather best, otherwise 
that on top will crumble up and fill up the interstices underneath. 

II The geological age of coal is a fair guide to its liability to heat, anthracite 
being the safest to store and ligir le the most dangerous. A good guide is the 
weathering effect on a sample rather prominently exposed and occasionally 
moistened with water by hand, that which readily crumbles up being the most 


26 


ILLINOIS ENGINEERING EXPERIMENT STATION 


dangerous but, of course, a great deal depends on the composition of the coal, 
considering the impurities and foreign material that may be mixed with it. ’ ’ 

The figures given in Table 4 indicate that a mixture of kinds and 
sizes increases the hazard; but these figures are by no means con¬ 
clusive as to the effect of mixture of kinds of coal, for the question¬ 
naires show that the mixtures which fired contained fine coal and this 
may have been the determining factor, rather that the mixture of 
different varieties of coal. 


Table 4 

Results of Mixture of Sizes and Kinds of Coal 



Questionnaire A 

Questionnaire B 


Mixture of 

Same Size 

Mixture of 

Same Size 


Sizes and Kinds 

and Kind 

Sizes and Kinds 

and Kind 


No. 

Per Cent 

No. 

Per Cent 

No. 

Per Cent 

No. 

Per Cent 

Fired. 

31 

69 

14 

31 

23 

30 

52 

70 

Not fired. 

12 

36 

21 

64 

39 

17 

185 

83 


15. Effect of Depth of the Pile .—There is a rather common 
opinion that heating is most likely to occur about five feet from the 
surface. The table given on page 187 of Circular No. 6 of tempera¬ 
ture observed by the Cleveland, Cincinnati, Chicago, and St. Louis 
Railroad at Hillary, Illinois, shows the highest temperature to occur 
at points five to ten feet from the top of the pile and that, in general, 
there is a gradual decrease in temperature below this maximum point. 

J. H. Anderson says*: 

“From previous experience we found the warmest place to be between 6 and 
8 feet deep from the surface; so from this we established a depth of 7 feet as the 
standard depth to record temperatures. ’ ’ 

John Morison saj^sf : 

“ It is usual to find that heating commences at a depth of about 5 feet, and if 
left alone it will spread downward until the coal fires. ’ ’ 

If coal is so piled that the fine portion stays on top of the pile and 
the lumps roll to the bottom, a point will occur in the pile where the 


* Trans. Inst, of Marine Engineers, Vol. 30, p. 83, June, 1918. 
t North of England Institute*, Feb. 9, 1918. 




























BITUMINOUS COAL STORAGE PRACTICE 


27 


air supply will be just sufficient to cause combustion of the fine coal 
but not sufficient to carry away the heated gases. Just where this 
point will be depends on the height of the pile, kind of coal, and 
method of storage. The replies to Questionnaires A and B as given 

Table 5 


Effect on Spontaneous Combustion of Depth of Coal Pile 



Questionnaire A 

Questionnaire B 

Depth of Pile 

Fired 

Not Fired 


Fired 

Not Fired 



No. 

Per Cent 
of 

Given 

Depth 

No. 

Per Cent 
of 

Given 

Depth 

Total 

No. 

No. 

Per Cent 
of 

Given 

Depth 

No. 

Per Cenl 
of 

Given 

Depth 

Total 

No. 

8 ft. or less. 

2 

33.33 

4 

66.67 

6 

26 

18.44 

115 

81.56 

141 

8 ft. to 20 ft. 

21 

52.50 

19 

47.50 

40 

37 

32.17 

78 

67.83 

115 

Over 20 ft. 

21 

67.74 

10 

32.26 

31 

5 

41.67 

7 

58.33 

12 

N ot stated. 

1 

1 

7 


35 










Totals. 

45 


33 


78 

75 


228 


303 


in Table 5 indicate that the percentage of fires increases as the depth 
of pile increases. While the evidence seems to show that fires are 
more common in deep than in shallow piles, the reason for this is 
by no means certain, but any one of the following conditions may 
contribute to the result: 

(1) There is less opportunity for the air to circulate 
through the pile and to carry off the surplus heat. 

(2) The air and gases gradually rising through the 
pile and increasing in temperature as they do so, may finally 
reach the temperature of spontaneous combustion of the coal. 

This opinion is held by many, but if it is true, the greater 
number of fires should be found near the top of the pile. 

(3) There will usually be increased breakage and an 
increased amount of fine coal which is the portion of the 
coal most liable to spontaneous combustion. 

(4) There is greater difficulty in watching the pile 
and in detecting incipient heating. Consequently, fires de¬ 
velop in deep piles without detection more readily than in 
low piles. 





































28 


ILLINOIS ENGINEERING EXPERIMENT STATION 


16. Affect of Quantity of Coal in Storage .—Table 6 indicates 
that the liability to fires increases with the size of the pile, but the 


Table 6 


Effect on Spontaneous 


Combustion of Quantity of Coal in Storage 



Questionnaire A 

Questionnaire B 

Fired 

Not 

Fired 

Total 

Fired 

Not 

Fired 

Total 

Quantity 

No. 

Per cent of 
given size 
of pile 

o 

£ 

Per cent 
of Size 

Total No. 

o 

£ 

Per cent 

of Size 

6 

£ 

Per cent 

of Size 

Total Size 

Less than .'500 t ons. 

2 

50 

2 

50 

4 

35 

18.61 

153 

81.39 

188 

500 to 1000 tons. 

5 

50 

5 

50 

10 

11 

24.44 

34 

75.56 

45 

1000 to 10 000 tons. 

18 

66.67 

9 

33.33 

27 

26 

40.62 

38 

59.38 

G 4 

10 000 to 100 000 tons. 

11 

47.83 

12 

52. 17 

23 

0 


3 


3 

100 000 to 1000 000 . 

8 

66.67 

4 

33.33 

12 




()ver 1 000 000 tons. 



1 

100.00 

1 






Not stated. 

1 




1 

3 


0 


3 











Totals. 

45 


33 


78 

75 


22S 


303 


same considerations that make the evidence inconclusive for increased 
hazard with increased depth, apply here; also the term, Quantity in 
Storage, is often indefinite. Ten thousand tons stored in one pile 
thirty feet high is probably more of a fire hazard than the same amount 
spread out in a pile only five feet high; but this and other conditions 
of piling are not evidenced by the statements in the replies received 
under the heading, Amount in Storage. The difficulties of storing 
and watching a large quantity may increase the fire hazard, but a 
large quantity is not per se more dangerous than a small amount. 


17. Effect of Methods of Piling. —A study of the effect of the 
methods of piling indicates that the lowest percentage of fires occurs 
where the coal is stored by hand. It is, however, only the small low 
piles which are piled by hand, and as pointed out previously, the 
depth of the pile and to some extent the quantity of the coal piled 
are factors in 1 lie liability to spontaneous combustion. Any mechanical 
method of piling should be so devised that there will be the least 
possible segregation of the sizes of coal and the least possible breakage 
in handling. The coal should be distributed in layers over the whole 



















































BITUMINOUS COAL STORAGE PRACTICE 


20 


or a considerable part of the pile and not dropped at one point 
so as to produce a conical pile. In a conical pile the fine material 
is generally found at the center and the lumps at the outside and 
toward the bottom of the slope; this arrangement gives a passage- 
w r ay for air to enter the pile and to reach the fine coal near the center, 
which is the most liable to spontaneous combustion. A number of 
fires have started at a point within the pile where the flow 7 of the air 
current was obstructed by the fine coal, thus establishing a condition 
in which the material most liable to spontaneous combustion was in 
contact with an excessive amount of oxygen. On account of the rapid 
oxidation of fine coal, the air current passing through such coal should 
be greater than that passing through larger sizes, while if the coal 
segregates in piling just the opposite condition is set up. To prevent 
breakage the clam-shell or other bucket should be low r ered near to 
the surface of the pile before being dumped. 


Table 7 

Effect on Spontaneous Combustion of Method of Piling Coal 


Method 

Questionnaire A 

Questionnaire B 

Total 

Fired 

Not 

Fired 

Total 

Fired 

Not 

Fired 

Shoveled by hand. 

UA 

l 

314 

6 

201 

35 

106 

Dumped from wagon. 

1 


Wheelbarrow. 

1 

i 

4 

2 

2 

Dumped from truck. 


4 


4 

Wheeled scraper. 

2 

2 



Dropped from car. 




9 

13 

3 

0 

Crane (locomotive). 




7 

0 

Conveyor. 




5 

4 

1 







Dropped from car on trestle. 

1 

1 





Elevator. 


7 

2 

3 

4 

Bridge. 





2 

Hydraulic. 

A* 

l 

At 

1 





In hopper. 





Not stated. 


58 

21 

37 

Clam shell. 

TA 

^A 

lAi 

17 M 



Crane. 

18 








Dodge storage system. 

l 

1 





Belt conveyor. 

3 

1 

2 




Elevator. 

1 

1 




Bridge. 

2 

2 




Raising track on coal 

7 

3 

4 




Underwater. 

1 

1 




Not stated 

2 

2 










Totals. 

78 

45 

33 

303 

75 

228 


*■ A indicates that a storage pile was partly piled by one method and partly by another. 


































































30 


ILLINOIS ENGINEERING EXPERIMENT STATION 


18. Causes of Fires— The question, “What in your opinion was 
the cause of the fire?” brought forth a number of reasons which are 
listed in Table 8 for the purpose of expressing popular opinion on the 
subject. 


Table 8 
Causes of Fire 


Causes of Fire 

Questionnaire A 

Questionnaire B 

Outside source of heat or aid to combustion in contact 
with coal 

2 


Wood in coal . 


7 

ITca.t, from hoilcr . 


3 

Tiif fpr from pt.ahlfis . 


1 

T? n s t from embedded steel rails. 


1 

Moisture or weather conditions 

2 

4 

blanket of snow . 

1 


Wet coal . 


7 

Contact wet anrl flry coal . 


1 

Wet ground or water under pile. 

2 

1 

Weather condition when coal was unloaded. 

2 




2 

Sulphur . . 

3 

9 

No reason evident except coal itself or method of piling 
Lack of ventilation . 


2 

Air circulation . 

3 


Segregation of sizes . 

8 

i 

Fine coal. 


l 

Mixture of coal. 

4 

O 

New coal piled on old coal . 

1 


Pile too deep. 

2 

l 

Quality of coal. 


l 

No opinion. 

15 

31 




Totals . 

45 

75 





19. Extent of Fires When Discovered .—The extent to which 
the fire was allowed to progress before discovery has been tabulated, 
not because it tells anything about the cause of the fire, but because 
it serves as an indication of the attention given the storage pile: 


Table 9 

Extent to which Heating Had Progressed 


Condition of Fire 

Questionnaire A 

Questionnaire B 

Odor only. 

0 

3 

Smoke. 

26 

39 

Ablaze when exposed. 

7 

13 

Ablaze. 

12 _ 

20 

Totals. 

45 

75 




























































BITUMINOUS COAL STORAGE PRACTICE 


31 


If precautions had been taken by the ordinary methods of watch¬ 
ing for fires and by being prepared to handle them promptly, none 
of the fires should have reached the point of blazing. If thermometer 
readings are taken, the heating of the pile can be stopped before it 
reaches the point where smoke due to combustion is given off. Temper¬ 
ature readings are not taken nearly so often as they should be in 
watching a storage pile but the following reports are of interest, as 
showing very imperfectly some relation between observed temperature 
and the other evidence of firing in a coal pile. The indefinite use of 
the term, fire, renders any generalization from these figures impossible 
as fire and heating are too often used synonymously. 


Table 10 

Temperature Observed in Storage Piles 


No Fires Observed 

Fires Observed 


132° Fahr. 

Short time before fire 

145° Fahr. Coal moved 

180° 

Smoking 

G9°-82° 

160° 

Smoking 

120° Coal moved 

140° 

Before smoke seen 


180° 

After smoke seen 


185° 

Smoking 


Temperature readings were not taken in any one of the 75 piles 
where fires occurred as noted in Questionnaire B and in only one case 
of the 303 reports of storage was there a temperature reading taken. 
This was 125 degrees Fahr., in the center of a storage pile. When 
the coal was removed from above this point, the pile cooled off. 

20. Danger Temperatures in Coal Piles .—One railroad advises 
loading out the coal if the temperature reaches 100 degrees, but as 
the temperature in the sun in summer over a large part of the United 
States is frequently above 100 degrees, this regulation would be im¬ 
practicable. Moreover, summer is the best time to store much of the 
coal on account of production and transportation conditions. 

J. H. Anderson* says: “Ninety degrees Fahr. was made a warn¬ 
ing temperature. One hundred degrees Fahr. was adopted as a 
danger reading at which point a trench was dug in the piled ’f 


* Trans. Inst, of Marine Engineers, Vol. XXX, June, 1918. 
t See page 36 for method adopted by Mr. Anderson to arrest rise in temperature. 







32 


ILLINOIS ENGINEERING EXPERIMENT STATION 


In Circular No. 6, 140 degrees was given as a warning tempera¬ 
ture; later studies indicate that if the temperature reaches 140 degrees 
the pile should be carefully watched and if the temperature con¬ 
tinues to rise rapidly to 150 or 160 degrees'the coal should be moved 
as promptly as possible and the coal thus moved should be thoroughly 
cooled before being replaced in storage. If the temperature rises 
slowly, although the pile should be carefully watched, it is not neces¬ 
sary to begin moving the coal at so low a temperature as when the 
rise is rapid, for the temperature may recede and the danger be 
passed. 

21. Detection of Coal Pile Fires .—The common methods of de¬ 
tecting the heating of a coal pile are: 

(1) By watching for evidences of steaming in the pile. 

(2) By noting the odor given off; bituminous or sul¬ 
phurous odors are evidences of heating. 

(3) By noting places where snow on a pile has melted. 

(4) By inserting an iron rod in the pile, and by noting 
its temperature with the hand after withdrawal. 

(5) By inserting thermometers into the pile and read¬ 
ing directly. 

(6) By using a pyrometer or plates connected with an 
automatic recording device. 

The first three methods are so self-evident in their application 
that it is unnecessary to discuss them in detail, but with a large pile, 
and particularly one where the heating is distant from the surface, 
a fire may reach an advanced stage without being detected by surface 
indications. 

Method No. 4, by which the temperature of an iron rod is noted 
with the hand, is a simple test, and one well-adapted to piles not 
over eighteen to twenty feet deep. By this means a janitor using a 
poker may keep informed as to the condition of the comparatively 
small amounts stored in house or apartment basements. 

Temperature readings with a thermometer or pyrometer furnish 
by far the best and most reliable method for keeping informed on 
the exact condition of a coal pile. 

lo get the temperature of the inside of a coal pile it is necessary 
firs! to provide an opening into which a thermometer or a pyrometer 





Fig. 1 . Pile of Screenings with Temperature Tubes, Closed at Upper 

Ends by Wooden Plugs 



























BITUMINOUS COAL STORAGE PRACTICE 


35 


may be inserted. Such openings may be made after the coal is in 
storage by driving pipes into the pile, but it is easier to place these 
pipes when the coal is being stored. Pipes left permanently in a 
pile are a disadvantage as they interfere with the appliances used 
to remove the coal. Instead of leaving the pipe in the coal pile it 
is sometimes necessary only to drive it and then withdraw it, the hole 
remaining open sufficiently to permit the insertion of the thermometer. 
To prevent the hole from filling with coal, an inverted funnel of paper 
is used in Canada. 

Such pipes as shown in Fig. 1 should be plugged at the upper 
end so as to exclude the outside air, for if ventilation is allowed 
through these pipes, a correct temperature reading of the interior of 
the coal pile is not obtained. 

If an iron pipe of small diameter is forced into the coal pile 
and is then moved up and down, the small amount of coal which has 
entered the pipe is removed. To prevent the pipe from filling up 
with coal as it is driven into the pile, a pointed plug may be placed 
in the end of the pipe and when the pipe has been forced into the 
pile to the desired depth the plug may be driven out by means of a 
rod inside the pipe. Before inserting the thermometer the pipe should 
be pulled up a slight distance so that the thermometer reading may 
give the temperature of the coal and not that of the iron pipe. 

One answer to the questionnaire described a method of making 
an observation hole by running a rod into the pile and then moving 
it around in a circle to form a hole sufficient^ large and open for the 
insertion of a thermometer. 

The Arthur D. Little Company, Incorporated, of Boston, makes 
the holes with a regular coal auger drill which is described as follows: 

11 These augers are regular mine auger drills and the total length of the 
auger can be extended indefinitely by sectional parts fitted with screw threads. 
It is preferable to have a handle for turning the drill, although this can be very 
easily accomplished by means of a Stillson wrench. ’ ’ 

J. H. Anderson* describes a method that he used with success 
for watching and regulating the temperature of coal piles. A storage 
pile of about 16 000 tons composed of a variety of coals which would 
not be stored under ordinary circumstances was chosen for experi¬ 
mental purposes, the depth of the pile varying at different points. 
The coal was stored on marshy ground above a ditch which had been 
filled with ashes to the level of the surrounding marsh. Some of the 


* Trans. Inst, of Marine Engineers, June, 1918. 



36 


ILLINOIS ENGINEERING EXPERIMENT STATION 


coal was deposited during very hot weather and some during heavy 
rain. Some was dry when unloaded from the steamer and some 
soaking wet. The conditions thus seemed to be particularly unfavor¬ 
able and extra care was exercised in watching the pile. Tempera¬ 
ture readings were taken at fourteen different places in the pile 
nearly every day at a depth of seven feet from the surface, as pre¬ 
vious experience had shown that the warmest place was between six 
and eight feet from the surface. This standard depth was also adopted 
for comparing the results obtained in piles in other parts of the 
county. Occasional check readings were taken at every foot depth 
in the pile. The temperature tubes % inch to 1 inch in diameter 
were driven to the bottom of the coal and were long enough to pro¬ 
ject two or three feet above the pile. Each tube had a numbered 
metal label on it for purposes of easy identification. In addition to 
the temperature pipes about fifty “vent’ 7 pipes were placed in the 
pile, not to ventilate the whole pile, but to draw off hot gases from 
local points. These pipes were 3 inches to 4 inches in diameter and 8 
feet long. About 8 inches along the length four holes were punched 
from the outside with a square tapered punch to about % inch; thus 
leaving a burr which prevented the coal from going down inside the 
pipe. To facilitate driving into the coal pile, the ends of the pipes were 
flattened chisel-shaped with an aperture about one-half inch left to 
prevent an accumulation of water at the bottom of the pipe and to 
permit the escape of air and gases. The pipes were driven to a depth 
of seven feet in the coal, leaving one foot projecting above the surface. 
A distinctive number was painted on each so that temperature read¬ 
ings could be properly accredited. 

By means of periodical temperature readings a close watch was 
kept on the pile. Ninety degrees Fahr. was made a warning tempera¬ 
ture and when this temperature was observed at any place, four tem¬ 
perature pipes were driven north, south, east, and west about ten feet 
from the warm pipe. The next day readings of the four pipes were 
carefully noted and the one showing the highest temperature was 
made the center and other pipes were put down around it. When 
the warmest spot was found in this way, a vent pipe was put in at 
this point and the rise in temperature was generally arrested. The 
smaller temperature pipes were then removed. One hundred degrees 
Fahr. was adopted as a danger reading and if the vent pipe failed 
to arrest the temperature and it reached 100 degrees, a trench one 


BITUMINOUS COAL STORAGE PRACTICE 


37 


fool deep was dug. If the daily readings were 100 degrees for, say 
three days, a spot would be trenched three feet deep. The danger 
temperature originally adopted was 95 degrees Fahr., and on four 
separate occasions trenching was done at one place, about 10 000 tons 
of material being removed. As the readings in this pile at no time 
reached 100 degrees Fahr., the trenching probably would have been 
unnecessary if additional vent pipes had been used. The coal was 16 
feet deep at this point. 

A somewhat similar method used by the Boston and Albany 
Railroad is described by S. Bisbee, Fuel Supervisor, as follows:* 

‘ 1 At one point 2-inch flues sharpened at the end were forced down to the 
Bottom of the pile and worked around, then withdrawn, leaving a hole 3 to 1 
inches in diameter, the holes being spaced 5 feet apart. If there is any tendency 
to heat, the number of holes is increased. Little trouble from spontaneous com¬ 
bustion. One fire started around a wooden pier, and another fire started in a high 
pile 10 feet from the bottom. Coal below this point found to be cool and no 
further trouble. Other fires occurred where piles had been placed on cinders. In 
no place did we have to dig out the coal for a distance of more than 40 feet, show¬ 
ing the spontaneous combustion was due to some local cause and that being re¬ 
moved there was no further trouble. ’ ’ 

22. Appliances for Beading Temperatures .— 

Thermometers 

The simplest form of thermometer for obtaining the tempera- 
ture inside such temperature holes is an armored maximum register¬ 
ing thermometer, as illustrated in Fig. 2. 


; i i i n 11111 j i m 11 M i i i i 11 m i i 111 i: 11 j 

2.0 .30 GO SO 

Fig. 2. Maximum Temperature Thermometer — Armored Type 

Thermostats 

The Illinois Central Railroad has used at several coal chutes, 
thermostats which were placed on the bottom plates of the coal bins 
so that if the coal heated in the bottom of a bin an alarm would be 
rung. These were installed in connection with an automatic hot 
journal alarm system furnished by the Western Fire Appliance Com¬ 
pany of Chicago. 

* “Storage of Coal by Railroads during 1918,” by II. II. Stock. Inter. Ry. Fuel 
Assoc. Proc., 1919. 




















38 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Recording Thermometers 

A recording thermometer, made by the Foxboro Company, for 
obtaining the temperature of a coal pile, is illustrated in Fig. 3. 
It consists of a recording pen that is operated by the vapor tension 
from a volatile liquid placed in a bulb at the end of a long flexible 
armored tube. This capillary tube is usually about five feet long 
but practically any desired length may be used. To register ac¬ 
curately the temperature of the hub must be about that of the at¬ 
mosphere. The instrument can be equipped with an electrical alarm 
so that a bell or other means of signal will be operated if the tempera¬ 
ture rises to a predetermined danger point. 

A cheaper installation consists of a dial thermometer as shown 
in Fig. 4, similarly connected to a bulb by a protected capillary tube. 
This form can also be arranged to give warning automatically when 
a given temperature is reached. 

The Zeleny Thermometer 

The Zeleny Thermometer system which is extensively used for 
observing the temperature of grain in storage tanks or bins has been 
adopted for observing the temperature of coal in storage in silos, 
pockets, or other storage bins. 

The apparatus consists of a reading instrument and a switch¬ 
board as shown in Fig. 5. From the contact points of the switch¬ 
board, wires lead to the various points in the bins where the tempera¬ 
ture is desired. The contact pins are properly labeled and when the 
switch lever is placed in contact with any one of these, the reading 
instrument indicates the temperature. In this way the temperature 
of many stations may be determined in a short time. The action of 
the instrument depends upon the thermo-electric properties of the 
metals used in the construction of the circuits. The wires leading 
into the coal are enclosed in heavy steel conduits so as to withstand 
the pull of the coal when the bins are being emptied. These steel 
conduits are supported at the top but are free to swing at the bottom. 
Naturally when there is coal in a bin the conduit is held stationary 
by the coal. When the bin is empty the lower end of the conduit mav 
be tied by a small rope to the bottom of the bin so as to keep it from 
swinging when the bin is being filled. In coal silos or bins of small 
diameter it may be sufficient to know the temperature of the coal 
along the walls or other supports in the bins; in this case the swing¬ 
ing steel conduits could be eliminated, and stations fixed at several 
points along walls or supports. 



Fig. 4. Indicating Thermometer — Long Distance Type 




























Fig. 5. Zeleny Thermometer System — Reading Instrument and 

Switch Board 






: 




jeeps® 8 

NO-MSifi 




' 


brown 

If j£&I£&2SL& n «M 


i-j:. u ; ? / H2L 

if-’ h*'.T; •»' .t®5& SjZpjjif* 

7 - ,*■ 




■ Tfh ' 1 ' 

Wifi** $?•?**** ?^c - i*' 


Fig. 6. Indicating Pyrometer — Millivoltmeter Type 






































Fig. 7. Indicating Pyrometer with Alarm Attachment 



Fig. 8. Indicating Pyrometer — Potentiometer Type 
















































































































Without 

Case 


Angie Type 





I'l.lilllv . / 




Joint end insulators 


With 

Case 


Fig. 9. Base Metal Thermocouples for Pyrometers 






























BITUMINOUS COAL STORAGE PRACTICE 


43 


Pyrometers 

Fig. 6 shows a portable electric pyrometer that has been used 
for obtaining the temperature of coal piles and Fig. 7 a similar alarm 
pyrometer. 

A recording pyrometer may be connected with a rotary switch 
having any desired number of points, each point suitably connected 
with a separate thermocouple that may be placed in any part of the 
coal pile. 

An indicating pyrometer of the potentiometer type for use with 
thermocouples is shown in Fig. 8. This reads in millivolts and it may 
be used with most types of thermocouples. The cold junction compen¬ 
sator on the instrument is also calibrated in millivolts. With this 
instrument it is necessary to use a transfer table of millivolts and 
temperature for the particular thermocouples used. The instrument 
will cover a range of approximately zero degrees to 340 degrees Fahr. 
Fig. 9 illustrates the type of base metal couple for use with this 
instrument. 


Thermocouples and Potentiometers 

Fig. 10 shows a method of observing temperatures in a coal pile 
of 10 000 tons described by T. W. PoppeA Observations were taken 
at points noted in the plan inside of one-inch wrought iron pipes 
welded to a point at the ends which were driven into the pile. The 
exposed ends were fitted with self-closing caps to prevent the entrance 
into the pipes of anything that might interfere with the introduction 
of thermocouples. Fifteen portable thermocouples were used and the 
wiring from these extended to a pole centrally located in the coal 
pile from which a permanent wire extended to the engineer’s office. 
The switches in the office were numbered and lettered to correspond 
with the pipes in the coal pile. An attendant placed the thermocouples 
in the pipes 1 to 15 row A and the readings were taken at the switch¬ 
board. As soon as the last couple had been placed in 15 A, the atten¬ 
dant began to move thermocouple 1 A to 1 B, etc., in numerical 
sequence, the time elapsing between the placing of 1 and 15 being 
sufficient to allow the couples to become heated to the temperatures 
in the several pipes. A recording pyrometer can also be used with 
the arrangement outlined. If a temperature of 250 degrees was in¬ 
dicated at any point, the nearby coal was at once moved to a point 


* Power. Nov. 5. 1918. 




44 


ILLINOIS ENGINEERING EXPERIMENT STATION 



Pyrometer 

Pecepfoc/e- 


Cab/e to Engineer's Off tee 

JL 



Fig. 10. Plan and Section of Coal Pile Showing Arrangement of 

Eeceptacles for Pyrometers 


near the place of consumption. In removing the coal from this pile 
to the boiler plant it was taken off in layers two feet thick over the 
whole pile, a gradual slope being maintained as shown to facilitate 
the use of a wheelbarrow. 

Mr. G. J. Congdon, Supervisor of Fuel of the Chicago Great 
Western Railroad, has described the use of a thermocouple and po¬ 
tentiometer by his road as follows: 


‘ ‘ The machine was purchased after the coal was on the ground and in order to 
get the thermocouple down into the coal it was necessary to drive old flues into the 
piles about 15 feet apart and in addition we have a portable, jointed pipe which can 
be driven into the piles at any place desired where the temperature may be thought 
to be rising. These pipes are perforated at the bottom and covered at the top in 
order to keep the circulation down as low as possible. 


“By means of the blank form (Fig. 11) which is filled out on the ground, 
a careful check is kept to see whether the temperature is rising or falling. It is 
a very simple matter to see how the coal is storing as the temperature can be com¬ 
pared from week to week and where there is an inclination to rise consistently 
we proposed to dig out that particular spot and use the coal at once in order that 






















































Pyrometer Test Record-Storage Coal 


BITUMINOUS COAL STORAGE PRACTICE 


45 


Pile Numbers 





















































- 













































0 














































9 





















































































































\ 









Date 

— 






1 








6 


EMPERATURE RECORD BLANK USED BY CHICAGO GREAT WESTERN RAILROAD 









































































































46 


ILLINOIS ENGINEERING EXPERIMENT STATION 


it may not spread to the rest of the pile, but we have never had to remove any 
of our coal on account of heating. 

11 The cables we use have five couples but it was never necessary to use but 
three of the couples as we had our coal piles only 10 to 12 feet high. The tem¬ 
peratures were taken by inserting this cable into the flue driven to the bottom of 
the coal or nearly so and leaving it to adjust itself to the temperature in the pipe, 
taking care meanwhile to keep the top of the pipe covered as much as possible. 
This takes only a few seconds. By changing the terminals on the cable to the 
potentiometer we could ascertain the temperature at the bottom, five feet from 
the bottom and ten feet from the bottom or by graduating the cable you could 
insert the same to any depth desired although on the whole I think but one tem¬ 
perature is about all you could get from the flue and that would be the highest one. 

“One of the bad features of the machine is the fact that it is very hard to 
get it even on top of a coal pile and unless it is level there is liable to be quite a 
difference in two readings even taken on the same day. I used a small spirit level 
for this purpose satisfactorily. ’ ’ 

23. Time when Fire Was Noted .—The length of time the coal 
was in storage before fire was discovered is shown by the graphs, 
Figs. 12 and 13 where the number of fires and the time in weeks are 



Fig. 12. Graph Showing Length of Time Coal Was in Storage when 
Fire Was Discovered (Questionnaire A ) 

the coordinates. These graphs show that most of the fires occurred 
in the first three months of storage. After that the hazard decreased 
as the time increased. This result is in agreement with the Chicago 
fire observations (see page 63), except that the peak of the graph 

































BITUMINOUS COAL STORAGE PRACTICE 


47 



Fig. 13. Graph Showing Length of Time Coal Was in Storage when 
Fire Was Discovered (Questionnaire B ) 

occurs at eight weeks for cases reported in answers to Questionnaires 
A and B, while for the Chicago fires it occurs at twelve weeks. 

These results confirm the opinion expressed in Circular No. 6 that, 
during the first three months after storage, particular attention should 
be given to watching a coal pile, and while the danger is by no means 
past after three months, the liability to fire seems to decrease rapidly. 
In this connection it should be noted that much of the coal involved 
in the answers to Questionnaires A and B was stored during the hot 
summer months so that the initial temperature was often high, which 
fact would tend to hasten spontaneous combustion. Some of those 
who store large quantities of coal do not feel that a pile is entirely 
safe until it has been in storage through one summer, but the ex¬ 
perience of the Commonwealth Company quoted on page 23 shows 
that fires may occur after a pile has passed one summer. 

J. H. Anderson says :* 

"As a rule the greatest danger is up to about three months from the time 
of taking the coal from the pit. ’ 1 

24. Reducing Temperature and Extinguishing Fires in Coal 
piles .—The following methods are employed for reducing the tempera¬ 
ture in a coal pile. 


* Trans. Inst, of Marine Engineers, Vol. XXX, p. 92, June, 1918. 































48 


ILLINOIS ENGINEERING 


EXPERIMENT STATION 


Moving the Coal 

The most effective method of combating a tendency to fire in a 
coal pile is by turning over the coal and exposing it to the air so 
that it may be thoroughly cooled. Care must be taken in exposing 
hot coal to the air, for, if the temperature is too high, as soon as the 
hot spot is opened out the mass will burst into flame and the fire 
spread very rapidly. Therefore, if there is evidence of a high tempera- 1 
ture the spot should not be opened out unless there are ample appli¬ 
ances at hand immediately to move the hot coal or water sufficient 
to put out any fire that may start and thoroughly to cool off the mass. 

Whenever the fire has reached the stage where the coal is actually 
ablaze, it may be necessary to use water but, in general, water should 
not be used if it can be avoided. 

The smoke and fumes given off by the burning coal make the 
work of moving a coal pile very unpleasant, especially in a confined 
space, and the workmen may become dizzy. This difficulty was over¬ 
come at a fire in the basement of the Manual Arts Building of the 
public schools of Charles Chy, Iowa, during the spring of 1916,* by 
installing an electrically driven fan in such a way as to draw the 
smoke out of the basement so that the workmen could shovel the coal. 
The fan also drew fresh air over the sliovelers, kept the space clear 
of smoke, and prevented the smoke from entering the building. 
When the fire was reached the smoldering coal was removed. The 
use of water on a previous occasion is said to have added to the 
trouble, but the reason is not stated. 


Use of Water 

The opinion is very commonly held that although fire in a coal 
pile is apparently extinguished by water, another fire is apt to break 
out in the same place. One reason for this was seen in at least one 
ot the Chicago fires which were visited during the summer and fall 
of 1918. It was noted that as a result of the heating of the coal, a 
coating oi tar had sealed the coal together in such a way that the 
seat of the fire at the center of the mass could not be reached by 
water. A coal pile also may have so much fine coal in it that the 
water can not penetrate to the point of the fire. 

1 lu* ineffectiveness ot a continued wetting of the surface of a 
coal pile in keeping down a fire was demonstrated by the Aurora, 


* Power, Vol. 44, p. 567. 



BITUMINOUS COAL STORAGE PRACTICE 


49 


Elgin, and Chicago Railroad at Batavia, Illinois, in connection with 
a storage pile of 12 000 tons of Warrick County, Indiana, mine-run 
which gave trouble from heating during the summer of 1918. A 
pipe (see Fig. 14) was suspended over the pile of coal and to this 
pipe were attached nozzles or sprinklers with which the coal was 
sprinkled continuously for six or eight weeks. 

The chief engineer of the plant reports that as soon as the water 
was turned off the fire started up again. He also states that in his 
opinion the fires were never thoroughly quenched throughout the 
piles,—that is, the water reached only the surface. The system was 
discontinued late in November to prevent freezing,'and a number of 
fires were reported in the piles during the winter, so that it became 
necessary to reclaim a great deal of the coal during February and 
March. 

A number of instances have been cited where perforated pipes 
were said to have been driven into heating piles and water injected 
into the pile at some depth through these pipes. There have been no 
personal observations of such an appliance upon which to base any 
conclusions as to the results of this method, but of six companies 
said by a manufacturer to be using the method successfully, one 
says that it was a complete failure, two have not tried such an appli¬ 
ance, one has not given it a sufficient trial to express an opinion, one 
said the appliance failed because tar clogged the nozzle, but thinks 
the apparatus would operate on certain kinds of coal, and one only 
had found it successful. 

In England those who store coal have reached the same con¬ 
clusion in regard to the use of water and J. II. Anderson says:* 


‘‘ In case of a fire in a heap of coal, although plenty of water should be avail- 
aide to quench out a fire if fames are seen issuing, still common sense must be 
used before we do even this, it being better to dig all round the fire; then, if 
possible, remove the hot coals away from the heap; then quench the material 
there. 

“ Plenty of warning will be given and the spot localized before there is any 
actual danger if a systematic method of temperature readings is carried out. In 
case of overheating, the seat of heating would be dug out. Great difficulty would 
be experienced to get water to a fire in the middle of a heap, as the fire would 
cause a certain amount of the coal to melt and form a coked mass. 

‘‘Of course, if the fire was in a receptacle that could be flooded out, such as 
a storage bin or a vessel’s hold, it may be the best plan to flood; but I certainly 
should not do this except when there was an actual fire that could not be treated 
otherwise. ’ ’ 


* Trans. Inst, of Marine Engineers, p. 92, June, 1918. 



50 


ILLINOIS ENGINEERING EXPERIMENT STATION 


It is evident that the exact effect of moistening coal requires 
further examination as the results of experiments thus far performed 
and the opinions expressed by different experimenters are not in 
agreement. 

In Technical Paper No. 16 the authors say :* 

1 1 The effect of moisture and the effect of sulphur on the spontaneous heating 
of coal are questions on which there has been a great deal of discussion and much 
difference of opinion. Very little experimental evidence has been brought to 
bear on either of the questions, and certainly neither is as yet settled. Richters 
has shown that in the laboratory dry coal oxidizes more rapidly than moist; but 
the weight of opinion among practical users of coal is that moisture promotes 
spontaneous heating. In not one of the many cases of spontaneous combustion 
observed by the authors, as representatives of the Bureau of Mines, could it be 
proved that moisture had been a factor. Still the physical effects of moisture on 
fine coal, such as closer packing together of dust or small pieces, may in many 
cases aid spontaneous heating.” 

In Technical Paper 113f the authors conclude: 

1 ‘ Heat is produced by wetting dry coal or a partly dried coal containing less 
than its normal percentage of inherent water. The relative quantity of heat 
generated depends upon the kind of coal and its deficiency in inherent water as 
referred to its maximum normal content. In other words the thermal effect of 
wetting varies directly as some function of the relative vapor pressure deficiency 
in the coal. The results of calorimetric determinations of the heat of wetting for 
different coals and for various percentage of water content are tabulated and 
illustrated by diagrams in the paper. Sub-bituminous coal from Wyoming that 
had been dried produced, by complete wetting, 19.2 calories of heat per gram of 
dry coal; brown lignite from North Dakota, 25.5 calories; bituminous coal from 
Franklin County, Illinois, 6.8 calories; and bituminous coal from the Pittsburgh 
bed, one calorie. 

‘ ‘ On the basis of known specific heats of these coals, if the values of the satur¬ 
ated coals are taken and it is assumed that no heat is lost to the containing 
vessel or to excess water, or by radiation, the heat developed would raise the 
temperature of the different coals as follows: 

Degr. C. 


Wyoming coal. 43 

Brown lignite from North Dakota . 64 

Franklin County, Illinois . 20 

Pittsburgh bituminous ... 4 ” 


* U. S. Bureau of Mines, 1912, “Deterioration and Spontaneous Heating of Coal in 
Storage,” by H. C. Porter and F. K. Ovitz. 

t U. S. Bureau of Mines, 1915. “Some properties of the Water in Coal,” by H. C. 
Porter and O. C. Ralston. 









Fig. 14. 


Sprinkler System Used by Aurora, Elgin, and Chicago 
Kailroad Company, Batavia, Illinois 
























. 














































BITUMINOUS COAL STORAGE PRACTICE 


53 


In Technical Paper No. 172 # the authors conclude: 

“The experiments showed that with Illinois coal thoroughly dried the rate 
of oxidation at ordinary temperatures was greater than with a comparative sam¬ 
ple of moist coal. On the other hand a thoroughly dried sample of Pittsburgh coal 
oxidized at a slower rate than a comparatively moist sample of the same coal. This 
difference between the two coals probably explains the discrepancies in the ob¬ 
servations of different experimenters. Richters found that a German coal ab¬ 
sorbed more oxygen when dry than when moist. Mahler, investigating a French 
coal, and Graham, investigating an English coal, found that moist coal absorbed 
more oxygen than dry. Evidently the rates of oxidation of different coals are 
not affected uniformly by moisture. ’ ’ 

The investigators named worked with small quantities of coal in 
the laboratory and used extreme conditions. Under actual conditions 
of storage both the coal and the air always contain moisture. Hence 
it seems doubtful whether water, other than the excess that actually 
wets the coal plays an important part in the rate at which coal 
oxidizes at the lower temperature, with consequent increase in the 
danger of spontaneous combustion. The experiments conducted on 
a working scale by Fayol, who could find no influence of wet weather 
on spontaneous combustion, and by the New South Wales Commission, 
which found that actual wetting of the coal produced a cooling effect 
during storage, tend to confirm this idea. 

The authors of Technical Paper 172 summarize their conclusions 
as follows: 

‘ 1 However, the opinion among coal shippers and consumers that there is more 
danger of spontaneous combustion during warm, wet weather than during dry 
weather may have another basis, the physical changes brought about by wetting 
the coal on the surface of the pile. Such wetting reduces the proportion of voids 
or open spaces in the mass. If the coal is divided into particles fine enough, the 
water will fill the voids completely and be held there by capillary attraction. Such 
a mass of coal and water on any part of a pile would block the passage of air at 
that place. As a result the conditions of ventilation in the pile before the wetting 
would be changed, so that, is some instances, the heat generated by the gradual 
oxidation of the coal would be retained until the temperature of ignition was 
reached. 

‘ ‘ For instance in a pile of coal formed in the usual manner with the fines at 
the top because of the rolling down of larger particles there would be a mass 
overlain with an impervious cover through the wetting of the outside surface. 
This cover would prevent air circulating by convection. Under such conditions 
oxygen would diffuse, as the coal absorbed it, from the lower parts of the pile to 


* IT. S. Bureau of Mines, 1917, “Effect of Moisture on the Specific Heating of 
Stored Coal,” by S. H. Katz and H. C. Porter. 



54 


ILLINOIS ENGINEERING EXPERIMENT STATION 


the covered part. The heat produced would be retained in the pile* and the tem¬ 
perature of the coal would increase at a rate dependent on the rate of oxidation 
alone; ignition temperature would readily be reached, and a spontaneous fire 
produced. The conditions described have been approximated to a degree in many 
storage piles of coal. In those piles moisture had a decided influence in the pro¬ 
duction of spontaneous fire. ** 

J. B. Porter* summarizes the effect of moisture as follows: 

“From the Reports of the Royal Commission on Coal Cargoes in England 
(1876) and in New South Wales (1897) one might conclude that coal containing 
much moisture would be likely to heat badly; yet out of 26 persons, who in 1876 
testified to the injurious effects of moisture, 25 admitted on cross-examination 
that they were simply repeating hearsay, and the other remaining witness was not 
available for cross-examination; furthermore, although the bulk of the testimony 
in 1897 was apparently to the same effect, the conclusions of the Commission 
did not give it much weight. 

‘ ‘ One would naturally expect that a coal containing moisture would be re¬ 
tarded in its heating because, until all the moisture has been evaporated, the tem¬ 
perature cannot rise above 100 degrees C. Yet, on the other hand, the steam per¬ 
colating through the surrounding mass, and condensing in the cooler parts, will 
heat as well as moisten them, and may thus tend to hasten oxidation in those 
parts. 

“It would seem that the experiments (of Richters) definitely prove that mois¬ 
ture hindered the absorption of oxygen of the coal in question, but this is not in 
accordance with the results of recent experiments by Porter and Cameron, and 
furthermore, there is no doubt that moisture will increase the rate of oxidation 
of pyrite; and whether the net results will be an increase or decrease in the final 
temperature must depend on the amount of pyrite present and on the amount of 
moisture. ’ ’ 

Fayol experimented with: 

1. Fresh fine coal. 

2. The same coal dried in ovens at a temperature not ex¬ 

ceeding 40 degrees. 

3. The same coal dried but sprinkled to make it damp but 

not wet. 

A number of piles of each kind were placed under similar con¬ 
ditions and temperature observations were made every day for several 
months. The temperature changes were found to be practically the 
same in all the piles and in no case did the temperature rise above 
50 degrees. 


* “An Investigation of the Co:ils of Canada.” 


Extra Vol., Canadian Dept, of Mines. 



MTUMlNOtTS COAL STORAGE PRACTICE 


55 


Parr and Kressmann* studied dry and wet coals at temperatures 
of 40, 60, 80, and 150 degrees C. Without exception in these tests 
wetting the coal increased the activity as shown by the ultimate 
temperature. It must be remembered, however, that these coals were 
stored at high temperatures which were raised by external heat. 

J. B. Porter says: 

•/ 

“A study of their results would seem to show that the wet coals did not heat 
on their own account until this externally applied heat raised them above SO 
degree C., which is fatal to many coals.’* 

J. B. Porter concludes his study as follows: 

“In conclusion it may be said that in all probability the temperatures of or¬ 
dinary coals under ordinary conditions of storage are not raised to any appreci¬ 
able extent by moisture. The question naturally arises, what was the basis of the 
once prevalent belief that moisture was an important factor in spontaneous 
heating? 

“This belief is, no doubt, chiefly due to the confusion of cause and effect on 
the part of persons who have discovered fires in coal storage. It is commonly ob¬ 
served that fires or hot spots in the pile are discovered shortly after rain storms, 
and that nearly always a hot spot is surrounded by damp or wet coal even if the 
main part of the pile is dry. The first case is easily explained by the fact that 
dry coal is so poor a conductor that the surface of a pile may show no indica¬ 
tion of a hot spot or even an incipient fire in the interior. A rain storm would, 
however, provide moisture enough to soak into the pile, and this moisture on ap¬ 
proaching the hot spot would be turned into steam which would work its way 
back to the surface and be observed, thus attracting attention to the hitherto un¬ 
suspected heating. The second explanation is equally simple. Air dry coal al¬ 
ways contains some moisture, and in lignitic coals there is also a very consider¬ 
able amount of combined water. In the case of a hot spot in the interior of a 
pile this moisture is driven off, either escaping at the surface as steam, or con¬ 
densing on the cooler coal in the neighborhood. Added to this there is, of course, 
an actual formation of water when the hydrogen constituents of coal are oxidized. 

“As an illustration of the second case it may be noted that during the ex¬ 
periments of the author at Outremont and Glace Bay vapor or condensed moisture 
was always noticed in the observation tubes in the neighborhood of hot spots even 
when the temperature w r as far below 7 the boiling point. ’ ’ 

The following extract from Circular No. 6 lias a direct bearing 
on the same point. In a private communication Dr. J. B. Porter says: 

< ‘ I fully appreciate the fact that nearly everybody experienced in the storage 
of coal objects to the use of water for quenching fires in storage piles. I ex- 


* Univ. of Ill., Eng. Exp. Sta. Bull. No. 46. 



5G 


ILLINOIS ENGINEERING EXPERIMENT STATION 


press scepticism as to the harmfulness of water quenching. Recent information 
strengthens this scepticism, and I have come across several cases of successful 
fire fighting by the intelligent use of water. The fuel agent of the Canadian 
Pacific Railway states that he always recommends the use of water if the fire 
is a small one, and particularly if it is detected in an incipient stage. His practice 
is to locate the hot spot by driving test rods into the pile and then to dig a pit 
one or two feet deep right over the center of trouble \ to drive and pull pointed 
rods or open pipes from it down into the heating mass and then to fill the pit with 
water, thus quenching the fire at the very center. At the same time if the fire is a 
large one he surrounds the whole heated part witli a water curtain made by digging 
a ring ditch one or two feet deep and perforating its bottom with a row of holes 
as in ventilation. This ditch like the central hole is kept full of water from the 
hose, and if there is a tendency for the fire to be driven outward from the center, 
it is quenched by the water curtain. 

‘ ‘ This method of putting out a fire is, of course, costly, but it is enormously 
quicker and less costly than that of digging out and results in far less loss of 
material. Personally, I am confident that it will prove successful in any ordinary 
case. ’ ’ 


Use of Carbon Dioxide and Bicarbonate of Soda 

A number of attempts have been made to utilize the smothering 
effect of carbon dioxide gas and solutions of bicarbonate of soda in 
ways somewhat similar to those used in the ordinary hand grenade 
or tire extinguishers of the Babcock and of similar types. The effect 
of C0 2 on fire is certain if it can be localized and applied where needed. 
The difficulty in a large coal pile is to confine the gases. The evidence 
as to the effectiveness of these agents in fighting fires in coal piles is 
by no means conclusive either for or against the method. 

Parr and Kressmann* have shown that the saturation of coal 
with a 3 per cent solution of bicarbonate of soda exerted very little, 
if any, retarding influence on the oxidation of the coal, although the 
saturation of the coal with a 10 per cent solution had quite a retard¬ 
ing influence. The experiments were carried on not for the purpose 
of finding methods which would extinguish a fire but which would 
prevent spontaneous combustion. 

In a report upon the Thomas Automatic Fire Extinguishing 
System, which uses a solution of bicarbonate of soda, the Pittsburgh 
Testing Laboratory has reported as follows: 

“In this method of fire extinguishing there are the following important 
factors: 


* “The Spontaneous Combustion of Coal,” Bull. No. 46, p. 45, Univ. of Ill., Eng. 
Exp. Sta. 



BITUMINOUS COAL STORAGE PRACTICE 


57 


1. Quenching effect of water alone. 

2. Smothering effect of carbon dioxide gas which is liberated at the 

surface of the burning material. 

3. Smothering effect of the water vapor liberated by the chemical 

force. 

4. Sealing and fire-proofing effect of the solid, non-volatile chemical. 

5. Chilling effect caused by the heat absorption when the bicarbon¬ 
ate of soda is broken up by the heat. 

"We have examined carefully the photographs and data concerning fire tests 
made with large quantities of combustible materials in box-cars and open piles. 
We note that these tests bear out all that is to be expected; namely, that water 
charged with bicarbonate of soda and applied under high pressure extinguishes 
large fires almost immediately. 

‘ ‘ A saturated solution of bicarbonate of soda contains about 10 per cent or 13 
ounces per gallon of water. Our practice has been to use from 2 to 4 ounces per 
gallon. ’ ’ 

In response to Questionnaire A , the following information con¬ 
cerning the use of carbonated water was received from Robert Smith, 
Engineer of the Michigan Alkali Company, Wyandotte, Michigan: 

‘ 1 The method used consisted of a tank in which the chemical was mixed and 
fed into the suction of a force pump which used the plant pressure of 65 pounds 
on the suction and boosted the same to 140 pounds. The nozzle was 10 feet long 
made of 1-inch pipe and it was forced into the pile, but I believe the best results 
were obtained by casting over the pile. 

‘ ‘ Our fire burned nearly two months, and towards the end seemed to increase. 
We used a solution of bicarbonate of soda and water and also turned over the pile 
and limited the pile to 25 feet. ’ ’ 

In connection with the fire of the Cleveland, Cincinnati, Chicago, 
and St. Louis Railroad, bicarbonate of soda was used and J. L. Hamp- 
son, Fuel Inspector of the railroad says: 

“Water is mixed with soda in proper proportions by a patented apparatus, 
controlled by J. A. Thomas of Columbus, Ohio. It is necessary to first put out 
the fire on the surface of the pile, then with a ditcher, steam shovel, or clam¬ 
shell, to throw this coal over to a depth of 4 or 5 feet and then extinguish the 
fire thus uncovered. This is necessary for the reason that this chemicalized water 
will not penetrate more than 4 or 5 feet in some places. 

“We did not use the method until we had given up the idea of saving the 
cool remaining on the ground at Bellefontaine and cannot, therefore, say what 
might have been the result if we had tried it earlier, for I am inclined to think 
that we would have saved much more of the coal. 


58 


ILLINOIS ENGINEERING EXPERIMENT STATION 


J. C. Dougherty, Coal Inspector for the New York Central Rail¬ 
road, says: 

“In one particular place where the pile was not over 10 feet in depth, a 
barrel of bicarbonate of soda was used. The entire barrel was scattered over a 
length not to exceed 30 feet. Water was turned in onto it and men drove bars 
into the coal and worked in the solution. Explosions were heard and several days 
later the fire was as bad as ever. ’ ’ 

Reports vary as to the effectiveness of the use of bicarbonate of 
soda in connection with fires on the Lake docks, and while it is un¬ 
doubtedly true that if C0 2 can be confined, it will extinguish a fire, 
yet the advantage of carbonized water over plain water, in connection 
with the digging out of hot spots has not been thoroughly demonstrated. 

Ventilation of Storage Piles 

Of the forty-five fires reported in connection with Questionnaire 
A, six piles had some sort of ventilating device, three having vertical 
pipes, and in one case the method was not stated. Of the thirty-three 
piles in which no fires occurred one was ventilated by means of ver¬ 
tical boiler tubes. 

In sixteen of three hundred and three storage piles reported 
on in answers to Questionnaire B, an attempt had been made to 
ventilate by means of iron or wooden pipes. In eleven of these six¬ 
teen piles fire occurred. These results do not suggest that ventilation 
as carried on is an efficient means of preventing spontaneous com¬ 
bustion and they agree very well with the results secured in the study 
of the fires in Chicago (see pages 73, 77). 

The subject of the ventilation of coal piles is one upon which 
there is a great difference of opinion, and the evidence is very con¬ 
flicting. It seems to be quite a common practice of Canadian railroads 
to ventilate their coal piles with a great deal of care, and it is the 
opinion of Professor J. B. Porter of McGill University and of S. II. 
Pudney, Fuel Inspector of the Canadian Pacific Railroad, that by 
means of proper ventilation spontaneous combustion can be prevented 
and the temperature of coal piles regulated to a very great extent. 
Other correspondents in Canada do not fully agree with this opinion. 
The experience of the railroads in the United States seems to differ 
widely upon this point, to judge from the replies to the questionnaires. 

Attention should be called to the fact that many pipes placed 
in coal piles are intended merely for observing temperatures with 


BITUMINOUS COAL STORAGE PRACTICE 


59 


no thought ot ventilating* the piles. (loal is a poor conductor of heat, 
and it is undoubtedly true that much of the so-called ventilation of 
coal piles has been inadequately done because only a few pipes have 
been placed irregularly throughout a pile. If ventilation is to be 
successful, it must be carefully done and pipes placed near together; 
but when so placed they interfere with rapid handling of the coal and 
increase the expense. The writers have not seen any of the Canadian 
coal piles that are reported to have been ventilated successfully, but 
a study of storage piles in the United States in connection with power 
plants has shown that the so-called ventilation is usually not well 
done and has been ineffective. 

The Cleveland, Cincinnati, Chicago, and St, Louis Railroad, at 
its Mattoon, Illinois, storage yard found that large shaft-like open¬ 
ings in the coal pile were beneficial in lowering the temperature of 
the coal. These openings were dug with a steam shovel and were 
approximately 8 ft. b} T 8 ft. by 10 ft. deep. 

At several Chicago storage piles it was noted that fires broke 
out near ventilation pipes, and at one place where the coal storage 
had been tiled horizontally with ordinary drain tile, the fire traveled 
along this tiling, which acted as a flue. 

The subject is worthy of more careful study and possibly of 
experiment, but it should be remembered that climatic conditions may 
have an important influence on the success of any ventilation method 
and what is successful in the cooler, drier climate of Canada may not 
be successful in the much warmer and moister climate of Illinois. 
Moreover, in Illinois there is not the same drop in temperature at 
night as there is farther north, or at a higher elevation as, for instance, 
in Colorado or New Mexico. Consequently there is much less oppor¬ 
tunity for a pile to cool off over night. 

Mr. S. H. Pudney in an address* before the Canadian Railway 
Club of Montreal, gives the cost of ventilating coal as five cents per 
ton and states that in the case of Dominion coals, the holes are placed 
two feet apart, and in the case of United States coals three feet apart. 
In this same connection attention is called to the use of trenches dug 
through the coal pile at intervals. This practice is used lr^ a number 
of railroads and has an effect similar to cutting a long pile up into 
a number of short ones by cross alley-ways. 


* Jour, of the Canadian Railway Club, Feb., 1919. 



60 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Summary of Methods of Fighting Fires 

The methods of handling the fires as indicated by the question* 
naires is shown in Table 11. 


Table 11 

Methods of Fighting Fires 


How Handled 

Questionnaire A 

Questionnaire B 

Water only. 

5 

11 

Coal moved—no water. 

32 

43 

Coal moved and water used. 

7 

19 

Sodium carbonate solution.. 

Not stated. 

1 

' 2 

Totals. 

45 

75 


25. Damage to Property and Loss of Coal from Fires .—In con¬ 
nection with the replies to Questionnaire A, it appeared that three 
out of forty-five fires involved a loss of property, but no statement as 
to the value was made. The following amounts of coal were reported 
lost as the result of such fires: 


Table 12 

Losses of Coal Due to Fires 


Coal Stored 

* Lost 

4700 tons 

200 tons 

800 “ 

75 “ 

35000 “ 

200 “ 

6000 “ 

10 “ 

8000 “ 

50 “ 

« 


In connection with nine of the fires reported in the answers to 
Questionnaire B, there was damage to the adjacent property, but in 
eight of the nine reported cases the loss was less than $100.00, while 
in one case the loss was something over $1000.00. 

The coal lost as the result of the fires was variously estimated 
at from less than one per cent to thirty per cent, but these figures 
are open to considerable question and at the best are only estimates. 
The average estimated loss by the fire varied from five to ten per cent 
of the coal in storage where the fires took place. 


























BITUMINOUS COAL STORAGE PRACTICE 


61 


26. A Study of Fires in Coal Piles in Chicago during 1918.— 
An excellent opportunity to study fires in coal piles was offered in 
Chicago during the summer and fall of 1918. Probably no better 
time or place could have been chosen for such a study, because, during 
that time the Fuel Administration was urging consumers to store 
coal, and, owing to the great variety of the industries in the Chicago 
district and the large amounts of coal brought in for coke and gas 
making purposes, practically all kinds of coal were stored, in spite 
of the zoning system for the distribution of coal. It is impossible 
to state with any degree of accuracy the total amount stored, but 
practically every dwelling had some coal in its cellar, manufacturers 
were storing all they could, and the railroads and public service 
corporations were storing to the full capacity of their yards. The 
Commonwealth-Edison Company alone at its different plants in the 
city had about 500 000 tons. The fires studied therefore occurred 
with amounts of coal varying from that found in an ordinary house 
cellar up to piles containing thousands of tons. 

The Commercial Testing and Engineering Company, 1785 Old 
Colony Building, of which Mr. Langtry is president, kindly placed 
its office at the disposal of the authors, and through the courtesy of 
J. C. Donnell, Chief of the Bureau of Fire Prevention and Public 
Safety, each morning a list of all the coal fires that had been reported 
the previous day was furnished. An attempt was made to visit all 
fires thus reported and to collect such information as would be of value 
in studying the problem. One hundred and twenty-one fires were 
visited and reported on, the Data Sheet (see Appendix I) being 
used to facilitate the gathering of uniform information. The fires 
visited have been classified under the following heads, depending on 
the cause of the fire: 

Class 1. Fires due partially, if not wholly, to outside sources of 

heat. 

Class 2. Combustion aided by foreign material in the coal. 

Class. 3. Fires due to no apparent cause except the kind of coal 
or the method of piling. 

Table 13 gives in tabular form a list of the fires studied, classi¬ 
fied according to the place in which the coal was stored, and to the 
cause of the fire, with the approximate amount in storage in each case. 


ILLINOIS ENGINEERING EXPERIMENT STATION 


02 


Table 13 

Classification of Fires in Chicago Coal Piles 


Places Where Coal Was Stored 

Class I 

Class II 

Class.IH 

Total 

Range of 
Tonnage 
in Storage 

Residences . 



1 

1 

10 

Apartments and flats. 

9 

2 ^ 

10 

27 

20 to 500 

Hotels, saloons, schools, churches, 






business buildings. 

3 

4 „ 

12 

19 

40 to 8000 

Fraternal homes. 

1 



1 

150 

Manufacturing plants. 

2 

13 

18 

33 

30 to 50000 

Coal yards. 


20 

15 

35 

40 to 8000 

Grain elevators. 



2 

2 

150 to 4400 

Railway. 



1 

1 

12000 

Public service corporations. 



1 

1 

10000 

Totals. 

15 

39 

00 

120 

10 to 5000 0 


A number of typical fires have been selected from those studied 
and detailed descriptions of these follow, arranged according to 
causes. 


Class 1. Fires Due Partially, if not Wholly, to Outside Sources of Heat 

In fifteen of the fires visited an outside source of heat seemed to 
be directly responsible for the spontaneous combustion of the coal. 
These sources of heat can be classified as follows: 


Hot Water Tanks . 

Hot Pipes . 

Hot Furnace . 

Hot Chimney or Breeching 
Hot Ashes . 

Total. 


1 

6 

4 

O 

O 

1 

"T-- - 

15 


The following is a summary of the information collected with 
reference to these fires. 

Thirteen of the piles contained mine-run and two screenings. 
Thirteen were under cover and two in the open. None was ventilated. 

In four piles there was a segregation of the larger from the smaller 
sizes. 

1 lie length of time which elapsed between placing the coal in 
storage and the discovery of fire is shown graphically in Fig. 15, in 
which the number of fires is plotted against the length of time as 
given in the following tabulation: 





































BITUMINOUS COAL STORAGE PRACTICE 


03 


Time in Storage 

3 weeks. 

8 weeks 
12 weeks. 

15 weeks 

16 weeks. 

No time stated 


Number of Fires 

. 1 

. 3 

. G 

. 1 

. 1 

. 3 


The peak of the graph is at twelve weeks; after that time the 
susceptibility of the coal to spontaneous combustion seemed to be less. 



Time /n Storage /n IVeeAs 

Fig. 15. Graph Showing Length of Time Coal Was in Storage when 
Fire Was Discovered (Chicago Coal Pile Fires, Class 1) 


The cases hereafter discussed illustrate a too common practice 
that indicates ignorance or disregard of the fact that should be well 
known by all who attempt to store coal; i. e., that liability to spon¬ 
taneous combustion increases very rapidly with increase in tempera¬ 
ture, and therefore a coal pile should be kept away from all external 
sources of heat. 








































G4 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Because of the urgent necessity for laying in a larger amount 
of coal than in ordinary times, in many cases more coal was bought 
for storage purposes than could safely be stored in the usual space 
provided. Consequently any available space was used without re¬ 
gard to its adaptability and this fact explains some of the fires of 
this class. It is probable, too, that the proper method of storing 
coal had not been brought to the notice of all concerned. 

A case where about seventy tons of Franklin County mine-run 
coal was stored in contact with a hot-water tank in the basement of 
a building is illustrated in Fig. 16. Heating of the coal started two 
or three weeks after the coal was placed in storage, and the center of 
the trouble was but a few feet from the tank. The janitor tried to 
keep the coal cool by wetting it with water two or three times per 
day, but finally called the fire department as the fire got beyond 
control. After the pile was flooded with water and the coal removed 
from around the hot-water tank, there was no more trouble. 

Six fires were noted where the coal was stored in contact with 
or in close proximity to hot pipes. These storage piles ranged in 
size from forty tons to a few thousand tons and in all cases the coal 
was either mine-run or screenings. 

A case where an uncovered sheet-iron smoke pipe leading from 
a furnace to the chimney was partially covered by coal is shown in 
Fig. 17. This pipe had several holes in it and at times became so hot 
that it could not be touched by the hand. After the fire, which re¬ 
sulted, was extinguished with water and the coal removed from the 
neighborhood of the hot pipe, there was no further trouble. Fig. 18 
shows hot steam pipes placed in an uncovered trench about which 
coal was piled; fire resulted. 

In four cases the heating was due to the coal being in contact 
with a hot furnace. All of these were in dwellings, and in every case 
the coal was mine-run. In two cases where the same kind of coal 
was stored in another part of the basement there was no trouble. 
Figs. 19 and 20 are views showing coal piled against furnace walls 
in basements. Fire occurred in both cases. Fig. 21 shows a chimney 
around which coal was piled; fire started in close proximity to the 
chimney. In another case a fire occurred in the basement of a flat 
in a coal pile at a point where hot ashes from the furnace had been 
piled against the coal. 


t 



Fig. 16. Coal Piled around Hot Water Tank 



Fig. 17. Coal Piled about Sheet Iron Smoke Pipe 













Fig. 18. Hot Steam Pipes about which Coal Was Piled, Causing Fire 



Fig. 19. Coal Piled in Contact with Brick Wall of Furnace 
(Coal Has Been Partially Removed) 










Fig. 20. Coal Piled in Contact with Brick Wall of Furnace 
(Coal Has Been Partially Removed) 



Fig. 21. Coal Piled around Base of Chimney 
(Coal IIas Been Partially Removed) 




























Fig. 23. Fire Starting in Coal Pile around Embedded Wooden Beam 



Fig. 24. Fire Starting in Coal Pile around Timbers of Trestle 

















BITUMINOUS COAL STORAGE PRACTICE 


69 


Class 2. Combustion Aided by Foreign Material in the Coal 

In thirty-nine of the fires visited the evidence indicated strongly 
that some foreign material such as wood, paper, rags, rosin, or sewer 
gas was responsible for starting the combustion as shown in Table 14. 

Table 14 


Fires Apparently Due to Foreign Material in Coal Piles 


Foreign Material 

No. 

Per Cent of 

Class II 

Per Cent of 

Total Chicago Fires 

Wood. 

31 

79.5 

25.8 

Mixture wood, paper, rags, etc. 

5 

12.8 

4.1 

Rosin. 

1 

2.6 

.8 

Sewer gases. 

2 

5.1 

1.6 

Totals. 

39 

100.0 

32.3 


Additional information concerning these fires may be summa¬ 
rized as follows: Of the thirty-nine piles in question, eighteen were 
mine-run, sixteen were screenings, four were No. 5, and one was No. 
3, No. 4, and No. 5 mixed. Thirteen of the piles were under cover 
and twenty-six in the open; two were ventilated and thirty-seven 
not; in twenty-seven there was a segregation of sizes, and in twelve 
no evidence of segregation. 

Fig. 22 is a graph showing the relation between the number of 
fires and the length of time in storage for Class 2 corresponding to 
the following tabulation: 


No. Weeks in Storage No* of Fires 

2 . 1 

6 . 3 

8 . 7 

12. 9 

1 a 4 


24. 1 

28.. 1 

No time stated. H 

As in Class 1, the most dangerous period was during the first 
twelve weeks. 

In view of the fact that 25.8 per cent of the total number of 
fires visited in Chicago were apparently caused by wood being mixed 




























70 


ILLINOIS ENGINEERING EXPERIMENT STATION 



Time in Storage/n Weeks 


Fig. 22. Graph Showing Length of Time Coal Was in Storage when 
Fire Was Discovered (Chicago Coal Pile Fires, Class 2) 


with or in contact with the coal, it is very important that those who 
store coal bear this in mind. Very often coal is stored around a 
wooden structure so that the wood is embedded in the coal. This 
is particularly the case where coal is placed in storage from a rail¬ 
road track on a trestle. 


There are two distinct ways in which such embedded wood may 
assist in starting combustion: first, by providing a flue along the 
timber for the circulation of an air current; second, by acting as a 
match in starting combustion at a lower temperature than that re¬ 
quired for coal alone. It has not been definitely proved that wood 
acts in the latter way and the theory to that effect is by no means 
universally accepted as being true. 


Figs. 23 to 30 illustrate cases where fires started alongside of 
or very near wood embedded in the coal piles in the form of supports 
to trestles or other structures, partition walls between piles, or en¬ 
closing walls for piles. 



































Fig. 25. View of Coal Pile Showing Timber Retaining Wall 
Anchored into Coal Pile by Wooden Supports 



Fig. 26. Partially Burned Wooden Horse Removed from Coal Pile 



















Fig. 27. Bracing Timbers Embedded in Coal Pile 

AROUND WHICH FlRE STARTED 



Fig. 28. Wooden Fence Partially Destroyed by Fire in Coal Pile, 
Apparently Due to Contact of Coal with Timbers of Fence 












BITUMINOUS COAL STORAGE PRACTICE 


73 


Fig. 23 shows a fire that was detected by smoke coming out 
along a beam embedded in the coal. Upon digging down into the 
pile the seat of the fire was found near the end of the beam. In a 
somewhat similar case fire started about an old coal retarder that 
had been surrounded by mine-run coal to a depth of twenty-five feet 
at the place where the fire occurred. Fig. 24 shows a very common 
condition. Smoke coming out along a track laid on top of a trestle 
indicates that a fire has started down in the pile. Such fires are usually 
found next to the leg of the trestle when the pile is dug into. In 
one case a fire was found at every leg of the trestle about which the 
coal had been dumped. Fig. 25 shows a common way of anchoring 
a timber retaining wall by means of timbers placed in the coal pile. 
Fire occurred in this pile but it was impossible to locate exactly the 
point of origin. A number of fires could be traced to no other cause 
than to similar wood anchors in the coal. Fig. 26 shows a wooden 
horse which formed part of a wheelbarrow runway that had been 
covered up with coal. Two of the legs are burned off at the end. 
Fig. 27 shows braces for a timber partition wall embedded in coal; 
a fire started around these braces. In another case a fire started 
about a plank carelessly left in a coal pile. Fig. 28 shows an en¬ 
closing wooden fence along which a fire started in a pile of Saline 
County screenings. A plank embedded in the pile, but projecting 
from it, thus furnishing a flue for air to enter the pile, was the 
apparent cause of fire in another case investigated. A pile of Pana 
No. 5 coal about some old partitions caught fire apparently near one 
of these partitions. In many coal yards the flooring under the coal 
piles is of wood and at a number of fires the origin was traced directly 
to this wooden floor. At other places where pieces of wood were em¬ 
bedded in the coal it was found when the coal was removed from the 
pile, that the hottest places were about these pieces of wood. 

Fig. 29 shows a case where an attempt was made to ventilate a pile 
of screenings by placing horizontal wooden tubes about six inches 
square (indicated by arrows) in the pile as it was put in storage. A 
fire developed very close to one of these ventilating tubes. Fig. 30 
shows an attempt to ventilate screenings by means of vertical wooden 
tubes (indicated by arrows). Fire developed very near these tubes. 

Five of the fires visited were apparently caused by an accumula¬ 
tion of wood, paper, rags, etc, mixed in with the coal. At a scivice 
station visited, 180 tons of mine-run coal were placed in storage in the 


74 


ILLINOIS ENGINEERING EXPERIMENT STATION 


basement; spontaneous combustion occurred near the center of the pile 
and on removing the coal it was found that at this place there was a 
considerable amount of wood and rubbish mixed with the coal. 

At a cold storage warehouse a fire developed in the storage pile 
at a point where there was a large amount of rubbish mixed with the 
coal (See Fig. 31). From this point the fire traveled toward a false 
bottom of wood which served as a flue. 

A most interesting case of fire was noted at a yard where about 
2500 tons of three-inch screenings from Murphysboro, Illinois, was 
placed in storage. Rosin had formerly been stored in this yard, and 
before it was used for coal storage a flooring of boards was laid on 
the ground over small quantities of accumulated waste rosin. The coal 
was piled on these boards, and within two months spontaneous combus¬ 
tion developed. When the coal was dug out with a crane, it was noticed 
that as the crane approached the bottom of the pile, the heat became 
more intense, and at the bottom there was a layer of coke about one 
foot thick on the boards which were burned to charcoal. A large 
quantity of molten rosin was mixed with the mass; the same condition 
was noticed at three different places in the pile. It is believed that the 
pressure and a slight heating of the coal caused the rosin to flow up 
through the space between the pine boards. Here it became mixed 
with the coal, and the kindling temperature of the mass was lowered to 
such an extent that it readily took fire. The kindling temperature of 
samples collected was so low that they could very easily be lighted by 
the flame from a match. 

Two fires which occurred in basements of buildings started imme¬ 
diately over sewer outlets. There is no direct evidence that the gases 
from these sewer outlets caused the fires, but sewer gases are apt to be 
moist and hot and the proximity of the point where the fires started to 
the sewer outlets suggests that such gases raised the temperature suffi¬ 
ciently to cause, or at least materially to aid combustion. 

One fire occurred in Chicago in clean sized No. 3 coal and the only 
explanation was that the coal had become heated by hot air entering 
the pile through a flue which led directly from the top of an adjoining 
boiler house. 





P -M m 




Fig. 29. View of Pile of Screenings with Horizontal Wooden Vents 
(Indicated by Arrows) near which Fire Developed 



Fig. 30. 


View of Coal Pile, with Vertical Wooden Vents 
Arrows) near which Fire Developed 


(Indicated by 















Fig. 32. View of Coal Pile Ventilated with Iron Pipes which Acted as 

Flues; Fire Occurred 


Fig. 31. Wood and Rubbish in Coal Pile around which Fire Started 


















BITUMINOUS COAL STORAGE PRACTICE 


77 


Class 3. Fires Due to No Apparent Cause except the Kind of Coal, 

or the Method of Piling 

In the case of sixty-six fires visited there was no apparent cause 
for the heating except in the kind of coal or in the method of piling. 
In a number of instances it was extremely difficult, if not impossible, 
to ascertain the exact conditions which caused the heating. 

The most striking factor appeared to be the size of the coal stored. 
Eiglity-six per cent of these fires occurred in mine-run or screenings, 
and in the case of those few fires which occurred in sized coal it was 
noted that there was a considerable amount of fine coal present, due to 
breakage in handling, weathering of coal, and improper screenings. 
The following table shows the number and percentage of fires occur¬ 
ring with each size of coal. 


Table 15 

Relation between Size of Coal and Number of Fires 


Size of Coal 

No. of Fires 

Percentage 

Mine run. 

35 

53.0 

Screenings and No. 5. 

22 

33.3 

Lump, 50 per cent, No. 5, 50 per cent. 

3 

4.5 

Nut. 

3 

4.5 

Lump. 

2 

3.1 

No. 4 Washed nut. 

1 

1.0 

Totals. 

00 

100.00 


Many believe that coal is safer if stored under cover, rather than 
in the open. A study of these Chicago fires would indicate that there 
is little difference whether the coal has a cover over it or not, for of 
the sixty-six fires in Class 3, thirty-four were under cover and thirty- 
two were stored in the open. 

At four of the storage piles where fires were investigated an at¬ 
tempt had been made to ventilate the piles by using perforated iron 
tubes. Fires started very close to some of these tubes which apparently 
furnished the air needed for combustion. It was noticed that the 
smoke of a cigar was drawn down into one pipe which thus acted as 
an intake, while the smoke was blown outward at another pipe which 
served as a chimney; thus the pipes were producing a circulation of 
air through the pile. 

Fig. 32 shows an attempt to ventilate with iron pipes, which was 
not effective, as fire resulted. 


















78 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Special attention was paid to the results of segregation or pyra- 
midincj of the coal, as it is sometimes called, when unloaded into the 
storage piles. Coal will naturally segregate into different sizes if it 
is continually dumped on one spot as the pile is built up, the fine coal 
remaining at the center of the pile and the larger sizes rolling to the 
bottom; thus flues are formed that carry the air to the fine coal which 
oxidizes easily. This segregation of sizes was apparently the cause of 
many fires, as it was noted frequently that fires started near the place 
where coal was shoveled into a basement through a window. At this 
point there would be a natural segregation of sizes. The fire was 
usually found in the fine coal. Table 16 shows the importance of this 
item: 

Table.16 


Relation between Segregation of Sizes in Piling and Number of Fires 



No. of Fires 

Percentage 

Sizes segregated. 

57 

86.3 

Piled uniformly. 

1 

1.6 

No information. 

8 

12.1 

Totals. 

66 

100.00 


The relation between time in storage and number of fires was as 
follows: 


No. Weeks in Storage No. of Fires 

3 . 3 

4 . 2 

5 . 7 

6 . 4 

8 ... 6 

10 . 7 

12 ... 11 

14. 3 

16. 4 

22 . 3 

26. 2 

No time stated .14 


Total . . 


Fig. 33 is a graphical presentation of the information contained 
in the above table, and shows that as in the other classes of fires con¬ 
sidered (see Figs. 15 and 22) the most dangerous period is during-the 
first twelve weeks. 
































BITUMINOUS COAL STORAGE PRACTICE 


79 



Time in Storage in Weeks 

Fig. 33. Graph Showing Length of Time Coal Was in Storage when 
Fire Was Discovered (Chicago Coal Pile Fires, Class 3) 


27. Summary of Data from All Types of Chicago Fires .— 


Classification according to General Causes No. Per Cent 

Class 1. Outside source of heat.15 12.5 

Class 2. Foreign material in pile. 30 32.5 

Class 3. No apparent cause except kind of coal or 

method of piling.fi6 55.0 


Total number of fires. 120 100.0 


Size of Coal 

Mine-run.66 55.0 

Screenings.40 33.3 

No. 5. 4 3 - 4 

No. 3, No. 4, and No. 5 mixed.1 

Lump 50 per cent, Screenings 50 per cent .... 3 2.5 

Nut. 3 2.5 

Lump.2 1.7 

No. 4 Washed Nut.1 


. 120 100.0 


Total number of fires . 



















































80 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Place of Storage 

No. 

Per Cent 

Under cover. 

. . . . 60 

50.0 

In the open . 

. . . 60 

50.0 

Total number of fires 

.120 

100.0 

Methods of Piling 

Sizes segregated. 

.89 

74.2 

Piled uniformly. 

. . . 1 

.8 

No evidence of segregation 

.30 

25.0 

Total number of fires 

.120 

100.0 


The relation between length of time in storage and number of 
fires was as follows: 


Length of Time in Storage 
(Weeks) 

No. of Fires 

No. of Fires 
(Cumulative 
Total) 


1 

1 

1 

3.•. 

4 

5 

4. 

2 

7 


7 

14 

0. 

7 

21 

8. 

16 

37 

10. 

7 

44 

12. 

26 

70 

14. 

7 

77 

16 .'. 

6 

83 

20. 

2 

85 

22. 

3 

88 

24. 

1 

89 

26. 

2 

91 

28. 

1 

92 

No time stated. 

28 


Total. 

120 



Fig. 34 shows graphically the relation between the length of time 
in storage and the number of fires occurring for all Chicago fires 
studied. 

Fig. 35 is a cumulative curve which shows the total number of 
fires occurring plotted against the time in storage. 

These data seem to show clearly that the following considerations 
should be taken into account in storing coal under the conditions pre¬ 
vailing in connection with the Chicago fires. 

1. Coal should never be subjected to heat from outside 
sources, such as hot pipes, boilers, etc. 

2. Foreign combustible material should be kept out of 
the pile. 




































BITUMINOUS COAL STORAGE PRACTICE 


81 


3. The coal should be piled in uniform sizes and segre¬ 
gation prevented. 

4. Sized coal only should be stored, if possible. 

5. It is immaterial whether the storage is under cover 
or in the open. 

6. The greatest liability to fires seems to be within the 
first three or four months and during that time special care 
should be taken to watch the pile for evidences of combustion. 

The illustrations given are selected from a great number of pho¬ 
tographs taken at more than one hundred fires visited in Chicago and 
in other cities, where the conditions were found to be similar in most 
respects to those found in Chicago with the exception that usually 
smaller amounts were stored. 



Fig. 34. Graph Showing Length op Time Coal Was in Storage when 
Fire Was Discovered (All Classes of Chicago Coal Pile Fires) 








































Tofa/ Number off/res of a// C/asses 


82 


ILLINOIS ENGINEERING EXPERIMENT STATION 



Fig. 35. Graph Showing Relation between Length of Time in Storage and 
Total Number of Fires (All Classes of Chicago Coal Pile Fires) 









































BITUMINOUS COAL STORAGE PRACTICE 


8 


1\ . Effects of Storage upon the Properties of Coal 


In Circular No. 6 the effects of storage upon the properties of coal 
were considered under the following heads: 


1. Appearance. 

2. Loss of heating value. 

3. Firing qualities. 

4. Spontaneous combustion. 

5. Coking and gas-making properties. 

6. Degradation or the increase in the amount of fine 
coal and dust due to breakage from handling and to slacking 
or weathering. 

7. Loss in weight. 


The conclusions in Circular No. 6 were as follows: 

(a) The heating value of coal as expressed in B.t.u. is 
decreased very little by storage, but the opinion is widespread 
that storage coal burns less freely than fresh coal. Experi¬ 
ments indicate that much of this deficiency may be overcome 
by keeping a thinner bed on the grate and by regulating the 
draft. 

(b) The coking properties of most coals seem to decrease 
as a result of storage, but coals vary greatly in this respect. 

(c) The deterioration of coal stored under water is neg¬ 
ligible, and such coal absorbs very little extra moisture. If 
only part of a coal pile is submerged, the part exposed to the 
air is still liable to spontaneous combustion. 


Although a study of the data gathered in connection with rail¬ 
road storage shows that a few consider that stored coal burns better 
than fresh and although similar opinions have also been given by those 
reporting on stationary power plants, yet the conclusion seems scarcely 
tenable. As pointed out by Parr in his bulletins, there may be a slight 
increase in B.t.u. value due to the washing out of the sulphur con¬ 
tents, thus giving a greater carbon content per ton in the resultant 
coal. This difference, however, is so slight as not to be appreciable in 
ordinary firing. 


84 


ILLINOIS ENGINEERING EXPERIMENT STATION 


It should be remembered that very often the apparent deteriora¬ 
tion in the coal taken out of storage is due not to any change in the 
coal but to the fact that the clam-shell or other device used for re¬ 
claiming, digs into the ground under the pile and mixes soil or refuse 
with the coal. It should also be remembered that the experiments at 
the University of Illinois, which indicated that storage coal can be 
burned as readily as fresh coal if a thinner bed is kept on the grate 
and if the draft is properly regulated, applied particularly to sta¬ 
tionary plants and that the draft cannot be so well regulated in locomo¬ 
tive practice. 

The following analyses furnished by W. D. Langtry confirm the 
conclusion that the decrease in heating value in B.t.u. of stored coal 
is very slight. 

Coal stored by the Indianapolis Abattoir Company for two years 
showed a decrease in B.t.u. of only 5.85 per cent, as indicated by the 
following analyses: 


Moisture . 
Dry Ash . 
Dry B.t.u. 


Coal Stored during 1918 

. . 13.66 
. . 14.33 
. . 12 393 


Same Kind of Coal in 
Storage for Two Years 

17.19 
14.17 
11 668 


Indiana fourth vein coal showed a falling off of B.t.u. of onlj- 
about' one per cent, as indicated by the following analyses: 


Coal from Same Mine 

Average of 472 ears Fuel Coal in Storage for 

one year 


Moisture.13.66 17.96 

Dry Ash.14.33 14.52 

Dry B.t.u. 12 393 12 200 

l 

Variation in heating value in coal from Murphysboro, Illinois, 
was very slight after fifty-one days in storage, as is shown by the 
following figures, and the slight difference could be easily attributed 
to variation in sampling and analyses: 


About 

Dec. 1, 1918 

Jan. 24, 1919 

Moisture. 

10.08 

10.65 

Ash. 

15.41 

14.90 

Volatile. 

31.28 

31.56 

Fixed Carbon . . . . 

43.23 

43.89 

B.t.u. (Moisture, ash, and 
sulphur free) 

14 848 

14 822 


BITUMINOUS COAL STORAGE PRACTICE 


85 


Another test of Murphysboro screenings placed in storage on the 
West Side in Chicago gave the following results: 



Coal from 
Boiler Room 
(or Fresh Coal) 

Coal in Storage 

4 Months 

Coal in Storage 
18 Months 


Per Cent 
Commercial 

Per Cent 
Commercial 

Per Cent 
Commercial 

Moisture. 

Ash .... 

Volatile .... 

Fixed carbon .... 

B.t.u. (moisture, ash, and sulphur free) 

10.25 

9.08 

33.18 

47.49 

14 816 

12.44 

9.16 

33.12 

45.28 

14 761 

11.89 

7.98 

33.28 

46.85 

14 713 


The coal in storage 18 months was piled 10 or 12 feet high and 
the pile was about 150 feet long and 25 feet wide, bulkheaded with 
wooden anchors running into the pile. It was reported that the tem¬ 
perature was at no time more than a few degrees over 100 degrees 
Fahr. 

The Engineering Supplement of the London Times for July 27, 
1917, in discussing the storage of coal, says: 

11 The loss due to weathering need not cause much concern since it would not 
be large from the pecuniary point of view. Colliery owners could in many cases 
select for storage the coals which, owing to their physical properties and chem¬ 
ical composition, are most immune from the effects of weathering or storage. 
Some tests on the effect of exposure on certain coals yielded the following re¬ 
sults : 


Description of Coal 

Storage Condition 

Effect on Calorific Power 

Bengal coal, India 

Large stocks exposed for 12 months 

Depth of stock 4 ft., aver. 


in the open 

loss 7.6 per cent 

Scotch anthracite cobbles* 

Samples exposed to all weathers in 
England for 2 x /i years 

Loss 3.3 per cent 

Scotch house coal* 

Sample exposed as above for 2 l /i 
years 

Loss 8.4 per cent 


* These coals, if stored in large quantities, would not show such a loss, as the total 
coal which is covered by the overlying layers would be protected from the effects of the 
weather.” 






























8(5 


ILLINOIS 


ENGINEERING 


EXPERIMENT 


STATION 


V. Storage Systems 

In Circular No. 6, Chapter V, the points to be considered in choos¬ 
ing a storage system and the requirements of an ideal storage plant 
were discussed. The following types of storage were described in con¬ 
siderable detail: 

✓ 

Hand-operated storage systems. 

Storage by motor truck. 

Pile storage from cars without a trestle. 

Trestle storage. 

Storage with side dump cars. 

Side-hill storage. 

Use of mast and gaff arrangement in storage. 

Locomotive crane storage. 

Parallel track storage. 

The trestle and crane system. 

«/ 

Circular storage. 

Steeple towers. 

The Hunt system. 

Bridge storage. 

Deep reinforced concrete storage bins. 

Underwater storage. 

Since the publication of Circular No. 6, a large number of storage 
plants have been investigated and the following descriptions include 
a number of new systems and also additional information about somo 
types that were described in Circular No. 6. 

28. Hand and Truck Storage .—There are no developments to re¬ 
port in connection with hand storage systems since the publication of 
Circular No. 6. 

The pile of coal stored by motor truck at the University of Illinois, 
as described in Circular No. 6, is still in storage and there have been 
no evidences of fire. The coal was screened 1% nut, in size when stored 
during 1918 and though the outside of the pile is now finely pulverized, 
the coal exposed by digging into the pile to the depth of a foot has the 
same appearance as when stored. 


BITUMINOUS COAL STORAGE PRACTICE 


87 


2 ( J. Pile {Storage .—Pile storage from cars which run on a track 
laid on the coal pile and raised from time to time is probably the 
method most widely used by railroads. It is also adopted to some ex¬ 
tent by commercial plants because it is the easiest in application, and 
requires only a small expenditure of money for permanent equipment 
and because the track can be moved from place to place as desired. 

The objections to the method are: 

(a) The pyramiding effect; that is, the segregation of 
fine coal at the center and top of the pile is intensified as the 
locomotive and loaded train crush the coal under the track. 

(b) It is not practicable to divide the coal by cross- 
passageways so as to make a number of small piles and thus 
render each pile easy of access for reclaiming. 

(c) When coal is piled in this way adequate track provi¬ 
sion for moving the coal quickly is apt to be neglected until it 
is time to move the coal and a track cannot then be put in place 
quickly enough to save the pile. Where this method is used 
the track should be moved from the top of the pile to the 
surface alongside the pile so as to provide for the rapid load¬ 
ing out of the coal, if necessary. The use of a standard rail¬ 
road ballast spreader to spread the coal on the pile is to be 
preferred to the ordinary method of dragging a tie through 
the coal. 

Mr. J. F. Hanson, Fuel Supervisor of the Cleveland, Cincinnati, 
Chicago, and St. Louis Railroad, says: 

“Our experience this year (1918) lias certainly demonstrated that coal can¬ 
not be stored successfully by dumping cars over the track and then raising the 
track through the coal.” 

On the other hand during 1917 the Illinois Central Railroad suc¬ 
cessfully stored run-of-mine in this way at two mines near Duquoin, 
Illinois. Although the method has been successfully used in a number 
of instances, it is the least desirable of all methods and is to be avoided 
if possible. 

Pile storage with the tracks placed alongside of the pile rather 
than on top is extensively used, and has not the same disadvantages as 
pile storage with the tracks raised on top of the pile. Fig. 36, shows 
long piles of the Missouri, Kansas, and Texas Railroad, Enid, Okla¬ 
homa. 


88 


ILLINOIS ENGINEERING EXPERIMENT STATION 


The track should be kept in place, so that the coal can be loaded 
out promptly, if necessary, and should not be moved as soon as the 
coal has been stored, as is sometimes done. Two tracks between piles 
give greater flexibility in switching cars than one, though, if necessary, 
one track will suffice as the locomotive crane can be used for switching 
the cars. When two tracks are used the crane runs on the track next 
the pile and unloads from cars on the parallel track. The height of 
such piles should preferably be limited to 16 to 20 feet and, to prevent 
pyramiding and breakage, the coal should be laid down in layers as 
thin as practicable, usually not over three feet thick and spread over 
the full width and length of the pile. It should not be piled up to the 
full height at one spot in the pile. The clam-shell bucket should also 
preferably be lowered to a point just above the surface of the pile be¬ 
fore being dumped so as to minimize breakage. 

Fig. 37 shows the standard system of the Missouri Pacific Rail¬ 
road. For coals that are liable to spontaneous combustion, the alley- 
ways across the piles are used; otherwise the piles are continuous. 

Locomotive cranes or ditcher appliances (see Figs. 38 and 39) 
afford great flexibility in placing coal in storage and in reclaiming it; 
they utilize equipment with which railroads and many industrial 
plants are usually already supplied. Piles can be made of any length 
that the available space permits and the width is limited only by the 
reach of the crane. They are also particularly well adapted for stor¬ 
ing coal in circular piles. 

With respect to usefulness for reclaiming, there is probably little 
difference between a revolving shovel and a locomotive crane or ditcher, 
but a shovel cannot be used for unloading from the cars. Any equip¬ 
ment of this kind requires a permanent investment in track for which, 
however, a rental may be charged to the storage account. 

30. Trestle Storage .—Trestle storage requires an initial per¬ 
manent investment in a structure which is used for only a short time. 
The legs of a trestle embedded in a coal pile are apt to be starting 
points for fires. In dumping from a trestle it is impossible to avoid 
pyramiding and the breakage is often excessive. The bents of a trestle 
interfere with the loading out of the coal and cleaning out of the bin. 
The combination of a trestle for unloading and a crane for reloading is 
satisfactorily used. 


BITUMINOUS COAL STORAGE PRACTICE 


89 


■ 80 - 


I J I 




;r 


$ 

■IsV 

1 'o 


60 


y 

§ 

n® 


60 '- 


r *»\ _ *:.i *V:.« 


$ 


v.v. 

yi 

It V* 


yi: I ^ y |g £; ' 

-^ J - 

0 ® y r /rs/’ rosit/on of Tracks 
> rSh/fr to Tn d ^/Pos/t/on when t/7/5 Space is f/Z/ec/i 




\ 


Y'o A 

•;» & tw r.-.. .- 

;$ ;•■••? ^ i;Vi^ jW i 


v; 

I 




& 
£ 




\ ' 


r T ;, 

> I I 

I 1 ‘ 

-J—/ V 




! i 
) \ 


_y 


N. 


O'P VO ^ 

^ ^/v5 econcf Posttfon of Tracks 


I 


r 


\ 


\ 1 


1 




; v 


_ 


7 v 


/ 



Fig. 37. Plan and Section Illustrating Standard Coal Storage System of 

Missouri Pacific Railroad 


An innovation in storage trestles is claimed by the Seaboard Air 
Line Railroad in connection with its trestle storage at Jackson and 
Savannah, Georgia. Trestles are constructed as shown in Fig. 40 and 
the ground is covered with plank. 1 he A. section extends the eutiic 
length of the pile and is made air-tight, except at the ends, the pur- 









































































uo 


ILLINOIS ENGINEERING EXPERIMENT STATION 



pose of this tine is two-fold: to help in shifting the coal from under 
the trestle and thus facilitate loading by crane, and also to act as a 
cooling agent by conveying cool air the entire length of the trestle with¬ 
out having it come in direct contact with the coal. Run-of-mine coal 
containing a large amount of slack was stored. An effort was made to 
store low sulphur coals, because the action of water on sulphur in coal 
forms sulphuric acid, which breaks up the lumps into slack. At no 
time was a temperature above 70 degrees noted in pipes placed in the 
piles. 

Fig. 41 shows the Standard Storage System adopted by the New 



\ 




Fig. 41. Plan and Section Illustrating Standard Coal Storage System 
of the New York, New Haven, and Hartford Railroad 
(Tonnage Given per Linear Foot) 

















































Fig. 36. 


Railroad Coal 


Storage Pile 


at Enid, Oklahoma 



Fig. 33. Ditcher Reclaiming Coal 





















Fig. 39. Ditcher Reclaiming Coal 



I ig. 42. Drag-Line Coal Storage and Coal Handling Plant of Southern 

Railway at Air Line Junction, Virginia 

















BITUMINOUS COAL STORAGE PRACTICE 


93 


York, New Haven, and Hartford Railroad at three coal storage yards 
recently installed. A trestle 1600 to 1700 feet long and 16 to 17 feet 
high runs through the center of each yard and on either side is a pair 
of parallel tracks. The trestle supports are wooden piling and the 
tracks on top of the trestle rest on steel girders. The two pairs of 
parallel tracks approach at the yard entrance. On one of the parallel 
tracks on either side of the center trestle a locomotive crane operates 
with a swinging boom which transfers the coal dumped from hopper 
bottom cars running on top of the trestle to piles built up about the 
trestle and also outside of the parallel tracks. The average height of 
the coal pile is 20 feet. The coal is trenched to a depth of 8 to 10 feet 
regularly throughout the pile and in addition ventilation pipes are put 
down to the bottom of the pile 40 to 50 feet apart. Temperature tubes 
are inserted in these pipes and readings are taken regularly for indica¬ 
tions of heating. 

Side hill storage is applicable only in certain districts and with it 
the pyramiding effect is exaggerated. 



Fig. 43. Plan and Section of Coal Storage and Coal Handling Plant of 
Southern Railway at Air Line Junction, Virginia 


31. Drag-Line Bucket Storage— Figs. 42 and 43 show in per¬ 
spective, in plan, and in section the drag-line type of storage used by 
the Southern Railway. The storage piles contain from 3000 to 10 000 
tons each, with a depth of not more than 10 feet. The railway cars 

















































































94 


ILLINOIS ENGINEERING EXPERIMENT STATION 


dump the coal into a track hopper, from which it is fed by a loading 
device to a bucket elevator. This delivers it either to the storage bin 
of the coaling station or to a gravity chute which discharges at about 
the center of the storage pile and from this point it is distributed over 
the area of the pile by the drag scraper. 

This scraper also returns coal from the storage pile to the track 
hopper and elevator for the supply of the locomotive coaling bin. The 
storage pile is of irregular form and is surrounded by poles, placed 
about 20 feet apart, to which is attached the cable line for operating 
the bucket. It has been found that the best height for these piles is 
about 12 feet. They are made of steel H-beams, each set in a concrete 
base and are connected at the top by a row of %-inch rods. 

The scraper bucket is operated by means of a double drum friction 
hoist driven by a 25 hp. motor geared directly to a countershaft. With 
this equipment the operator can take the coal delivered from the chute 
and distribute it between this point and the post to which the snatch- 
block is attached. To reach the space between two posts, lines may be 
fastened to them and the snatch-block attached to the lines. By shift¬ 
ing the block from pole to pole any point within the coal storage area 
can be reached. When it is necessary to supply the bin of the coaling 
station, the position of the bucket or scoop is reversed, its open end 
being turned toward the coaling station, the backhaul cable then be¬ 
coming the hauling line. 

Drag-line storage systems are somewhat less flexible than the 
locomotive crane type but they require less initial investment, for the 
motor, ropes, bucket, and posts are probably less costly than a crane, 
and no track investment is required. 

32. Silo Type of Storage Pockets .—The silo type of coal storage 
pocket has been used by a number of industrial plants for strictly 
storage purposes and by retail dealers and railroads for temporary 
storage and current supply. The silos are constructed of reinforced 
concrete, of steel plates, or of wooden staves and are often built in 
batteries of two or more with a capacity of 100 to 1000 tons. They 
vary in diameter from 14 to 30 feet and in height from 24 to 75 feet. 
Old steel tanks have been remodeled in some cases to serve as coal 
pockets. The silos are filled from hopper bottom cars which are un- 


BITUMINOUS COAL STORAGE PRACTICE 


95 


loaded through a track grating into the boot of an elevator which de¬ 
livers the coal at the top into a conveyor line running over the top of 
the silos and arranged for automatic dumping into any desired silo. 
Silos are usually set high enough above the ground so that the coal 
can be loaded out by gravity through chutes either into a conveyor 
for transferring the coal to a power plant, or into wagons; a screen¬ 
ing arrangement may be located at the discharge point. At the 
top of the silo, in order to prevent breakage, the coal may be dumped 
upon a zig-zag coal ladder consisting of a series of projections from 
the walls of the silo, the coal falling from one to the other so as to de¬ 
crease the height of drop. 

The advantages of the silo are: small ground space required, less 
labor required for loading and unloading, and the ease with which the 
coal can be transferred by means of elevators and conveyors from one 
silo to another in case of a rise in temperature. 

The disadvantages are: high initial cost of installation and exces¬ 
sive breakage when the coal is dropped through any great height, and 
the necessity of moving the entire contents of the silo below the heat¬ 
ing spot if heating occurs. 

It is believed by some that the danger of the coal heating is 
reduced to a certain extent because every load that is taken out of the 
silo shifts the position of the remaining coal. Such movement of the 
coal may also act injuriously by causing the circulation of air in an 
insufficient quantity. If heating occurs, the bin may be flooded with 
water, provided it has been constructed to withstand the pressure of 
the coal with the interstices filled with water. 

Fig. 44 illustrates a coal pocket of wooden stave construction, 
which consists of a battery of four silos 34 feet high, three of them 
being 20 feet in diameter and the fourth one only 16 feet in diameter. 
The storage capacity of the plant is about 1500 tons of anthracite. 

The coal is dumped from the car into a steel-lined concrete hopper 
from which it slides into a steel boot. It is then elevated by continuous 
buckets to a point over the bins, from which it is distributed as desired 
through several chutes and valves. To avoid excessive breakage it is 
lowered to the level of the coal in the different bins by a zig-zag coal 
ladder. The power is furnished by a 10 hp. electric motor. 

The cost of operating this plant is given by the II. M. Tuttle Com¬ 
pany of Bennington, Vermont, as follows. 


9C) ILLINOIS ENGINEERING EXPERIMENT STATION 

Plant Expenses for One Month 


1. Depreciation.$31.59 

2. lieal Estate Expense 

Tax apportionment.14.08 

Insurance.10.33 

Land and track rental.22.01 

3. Light and Power. 8.70 

4. Degradation 

Shortage in weight of cars and loss 
from screenings for 1259.04 

net tons at $.39 per ton.491.09 

5. Wages 

Unloading and yard employees. 202.46 

Total . $780.26 


Thus, since 1259.04 tons were handled during the month, the cost 
per net ton would be $0.62. The average cost per net ton for nine 
months was $0,554. 

The cost of silos similar to those shown in Fig. 44 was given in 
February, 1919, as $2.20 for a 400-ton bin to $2.60 for a 200-ton bin 
per ton of coal capacity for the materials on board cars at Rutland, 
Vermont, at the plant of the Creamery Package Manufacturing Com¬ 
pany, builders of such silos. Erection and freight are said to add not 
over fifty cents per ton. 

Fig. 45 shows a stave silo plant elevated for bottom discharge to 
retail trucks. 

Concrete or steel construction for silos has an advantage over 
wood construction as the repair bill is less, and the fire risk is greatly 
reduced. With reference to a concrete storage pocket, F. W. Stock & 
Sons,* Hillsdale, Michigan, under date of January 30, 1919, says: 

‘ ‘ The coal storage tanks erected about a year ago have proved a very success¬ 
ful investment for us as a manufacturing concern. To prevent spontaneous com¬ 
bustion the coal should be drawn in rotation from all the tanks and not from 
only one; otherwise, there is considerable chance of spontaneous combustion, 
particularly if the coal happened to be slightly damp when put into the tanks.” 


The Macdonald Engineering Company, Chicago, Illinois, builders 
of this plant, reports upon these silos after they have been operated 
two years, as follows: 


* Illustrated and described in Univ. of Ill., Eng. Exp. St.a. Circular No. 6, p. 95. 














Fig. 45. Wooden Stave Silo Coal Storage Plant, Arranged for Bottom 

Discharge 



















































BITUMINOUS COAL STORAGE PRACTICE 


90 


“One of the bins in this plant which is 28 feet in diameter ami 70 feet deep 
was kept continuously filled with coal from sometime in October, 1917, to August, 
1918. The contents in this time had not been disturbed to amount to anything. 
No perceptible rise of temperature was observed until sometime in August, 1918, 
when the moisture originally in the coal seemed to be pretty well evaporated and 
the temperature began to rise. We had equipped these bins with a means for 
Hooding them with water. About the first of September when the temperature 
was at the ignition point we tried an experiment and turned on the water. This 
resulted in so much steam and gas that it was discontinued, as our man feared it 
might produce an explosion. Immediately after shutting off the water we drew 
out 10 tons of the hot coal through the bottom discharge spouts of the bin. This 
coal was smouldering and the amount drawn seemed to include all that was on 
fire. We then closed the valves and sealed them air-tight with a putty of clay. 
Two or three days later an inspection showed that the trouble was over and the 
temperature nearly normal, since which time there has been no further increase in 
temperature. At the date of the heating we had 65 feet of coal in the bin and 
we found that the fire was located on the hopper bottom of the bin and occupied 
the space between the outlet openings and the manhole which was built in the 
vertical outside wall of the bin. The indications were that there had been just 
enough air ventilation between the outlets and this valve to furnish the required 
amount of oxygen for combustion. From this experiment it would seem that if 
the opening w r ere sealed perfectly air-tight there would be no rise in temperature. 
After using this plan for two years the only suggestion that the owners had to 
make is that they would use smaller bins for any future storage, so that if they 
had to change the coal from one to another there would not be so much to handle.’’ 

W. A. Joshel, wholesale and retail coal dealer of Geneva, Illinois, 
has two silos 60 feet in height and 18 feet in diameter. One of these 
is partitioned into four bins and the other into two bins by means of 
2x4’s laid flat. The silo walls are 6-inch reinforced concrete. There 
has been no trouble from heating; the coal is kept in motion by being 
constantly drawn out at the bottom. The breakage has been heavy 
and Mr. Joshel advises building silos much lower and either building 
more of them or increasing the diameter. He is able to unload a 42- 
ton car of anthracite, range size, from a hopper-bottom car in one and 
one-fourth hours with only one attendant, while a box car takes three 
times as long. Power is furnished by a iy^ hp. motor. The silos 
hold about 600 tons and the cost on the 1916 price basis was $7000, 
which is considered to be $700 too high, due to unusual foundation 
blasting and other difficulties. 

Fig. 46 shows a storage plant of the American Hominy Company 
of Indianapolis, Indiana. It is built of concrete in silo type and has 
a basement conveyor tunnel running the full length of the building. 
E a ch of the five concrete bins is 28 feet in diameter and 7o feet in 


100 


ILLINOIS ENGINEERING EXPERIMENT STATION 



Fig. 46. Side Elevation, Plan, and Section of Coal Storage Plant of 
American Hominy Company, Indianapolis, Indiana 













































































































































BITUMINOUS COAL STORAGE PRACTICE 


101 


height. The coal is received through a deep track hopper which will 
take the discharge from the longest coal car made and deliver it 
through a crusher to a vertical elevator which raises it to the top of the 
storage plant. The distributing arrangement is such that the coal may 
be delivered directly to the bunkers in the boiler-house or sent into 
the bins for storage. After being delivered into the bins it is trans¬ 
ferred from these bins by means of a belt-conveyor located in the base¬ 
ment of the building, elevated by a vertical conveyor at the end, and 
discharged through an automatic scale to a conveyor which delivers the 
coal to the boiler room bunkers. The advantages claimed for this form 
of storage are reduction in ground space, as well as the reduction of 
labor cost due to automatic handling of material. 

At this plant, during the summer of 1919, an explosion occurred 
in one of the silos while a small amount of coal that had heated badly 
was being drawn off at the bottom. The explosion had sufficient force 
to lift the roof slab a few inches and to carry away a small section of 
the side wall. The heating seems plainly traceable to an air leak 
around the outlet valves at the bottom which at first were not made air¬ 
tight. After the supply of air was shut off the heating ceased. 

33. Portable and Semi-Portable Conveyors .—The portable or 
semi-portable type of elevator or conveyor has been developed by a 
number of firms to supply means for storing and handling coal in 
smaller quantities and with less expensive machinery than by the use 
of cranes of either the locomotive or gantry type. 

These appliances consist essentially of a belt or bucket conveyor 
suitably supported and encased and moved about by means of wheels 
underneath or supported by a form of trolley overhead. Semi-port¬ 
able conveyors have one end fixed or pivoted, while the discharge end 
can be rotated. These conveyors vary in size from the small wagon 
loader type to the long portable type intended distinctly for storage 
purposes, the conveyor arm varying in length from 6 feet to 60 feet 
and in width from 12 inches to 24 inches. According to the catalog 
of the Barber-Greene Company of Aurora, Illinois, the capacity of 
belt conveyors and power required for different materials is given in 
the following table: 


102 


ILLINOIS ENGINEERING EXPERIMENT STATION 


a 

m 

< 

H 


w 

OS 

O 

h 

w 

> 

£ 

o 

U 

w 

hJ 

m 

Eh 

PS 

O 

eu 

pet 

o 

>H 

H 

M 

o 

■< 

o- 

■< 

U 




o 

CO 

CO MO b- 



i> 

»c 

\ss 

CO »o 



10 

X 1 

C0- 1C 1^ 



V. 

rH 

lO 

\cs 

co»o 1 ^ 



00 

CO CO u0 



>b 

co co >o 

T. 

« 

o 


b 

Tjt 

CO CO *o 

H 

O 

k-H 

H". 


39' 

coeo*o 

« 

s 


CO 

CO 

(MCOlO 

o 

eu 


CO 

CO 

(N CO CO 

W 

ft 

£ 

0 


o 

CO 

(N CO CO 

w 


CM 

HWCO 



Tjc 

(N 

£ 

1-HOI CO 



rH 

Ol 

£ 

1-hojco 



00 

rH 

£ 

rH rH CM 



»o 

rH 

\c* 

h\ 

H H CM 



b 

rH 

X 

rH rH rH 



f-i 

o <v 




o O 

E -p 

^OCD 

co a> »o 

rH 

& 

p 

o 

if- 

HM 

« 

w 

Ph 


Cement 

ooo 

CO 00 1* 

rH 




JO 

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Eh 


Earth 

Clay 

C)»ON 

CM CD rH 

rH 

Capacity 


Coal 

l> Tt< 00 

iH^N 


Coke 

o co e- 

HNlfl 

Width 
of Belt 
(Inches) 

<n oo 

i—i i-i OI 


































BITUMINOUS COAL STORAGE PRACTICE 


103 


It is claimed that, where material is delivered by gravity from 
the car directly to the conveyor, there is a saving of from 75 to 90 per 
cent in the handling cost and even where the material is shoveled to 
the conveyor half of the labor cost is saved. The power requirements 
are said to be from one to two kilowatts per hour for the short con¬ 
veyors and from three to five kilowatts for the long conveyors. Several 
types of conveyors used in coal storage are shown in Figs. 47 to 61. 

A typical method of using a combined fixed and portable system 
is shown in Figs. 47 and 48. The coal is delivered from the car into 
the boot of the fixed conveyor and at the delivery end builds up a 
conical pile, the height of which depends upon the height of the end 
of the conveyor and the amount of drop allowable. After the central 



Fig. 48. Circular Method of Piling Coal, Using Both Portable and 
Semi-Portable Conveyors — Plan and Section 









































104 


ILLINOIS ENGINEERING EXPERIMENT STATION 


pile has been built a concentric pile is built up by delivering the coal 
into a chute which at the bottom feeds the boot of a portable conveyor. 
This conveyor in turn builds up either a series of conical piles con¬ 
centric with the center pile as shown in Fig. 47 or a continuous, con¬ 
centric, conical pile as shown in Fig. 48. 

An application of this system built by the Barber-Greene Com¬ 
pany at Mooseheart, Illinois, is illustrated in Figs. 49 to 51. In this 
plant the coal is delivered from a railroad track hopper shown at the 
left in Fig. 49 into the boot of a vertical bucket elevator which at the 
top delivers the coal either into a cross-conveyor which carries it into 
the boiler house bunkers, or else to conveyors which carry it to the stor¬ 
age piles. 

In the original installation built in 1918, an inclined conveyor sup¬ 
ported on trestles was used. This conveyor delivered the coal either 
upon a single conical pile or, by means of a long chute and a semi-port¬ 
able convejmr, upon a concentric pile or several concentric piles as 
shown in Figs. 49 and 50. 

To reclaim the coal the process was reversed, the coal being taken 
from the storage pile by a portable conveyor, which delivered it to a 
semi-portable conveyor which, in turn, delivered it to the elevator. 

Experience showed that a large central conical pile at the end of 
the inclined conveyor was too high for safe storage; consequently 
this conveyor has been lowered so that it now runs horizontally and 
delivers to the belt of the portable conveyor. 

Fig. 51 shows the new plant at Mooseheart with four conveyors in 
operation. On account of the railroad cut, through which incoming 
cars run, it was found advisable to divide the storage equipment into 
two units, one on each side of this railroad. The conveyors operate 
with reversible motors and the receiving hopper can be changed from 
end to end according to whether the coal is being stored or reclaimed. 
The initial cost of the plant was $4600 and the cost of the storing and 
reclaiming is estimated to be about twenty cents per ton. 

Fig. 52 shows a portable conveyor used for storing directly from 
a railroad car and also for reclaiming directly into a railroad car. 
Fig. 53 shows a portable conveyor supported by cable, and if the 
ground permits, this system may be extended indefinitely. 

Fig. 54 shows a view of a portable conveyor made by the Automatic 
Coal Conveyor Company of Chicago and operated by means of an 



Fig. 47. 


Circular Method of Piling Coal, Using Both Portable and 
Semi-Portable Conveyors 



Fig. 49. Coal Storage Plant Using Fixed and Portable Conveyors at 

Mooseheart, Illinois 


J 














Fig. 50. Coal Storage Plant Using Fixed and Portable Conveyors at 

Mooseheart, Illinois 



Fig. 51. View op Recent Addition to Mooseheart Plant, 
Showing Four Conveyors in Operation 





















BITUMINOUS COAL STORAGE PRACTICE 


107 



Load/ M6 Ca* Fnon J&TOBAGC P>LC 


Tiuno Material By Using Cows .you UwpcR Car 


Fig. 52. Plan and Sectional Views Illustrating Methods of Storing from 
and Reclaiming into Railroad Cars with Portable Conveyors 



Fig. 53. Portable Conveyor Supported by Cable 
































































108 


ILLINOIS ENGINEERING EXPERIMENT STATION 


overhead trolley. This trolley can also be installed inside of a storage 
shed and used for placing coal under cover directly from the railroad 
car. . 

District of Columbia Storage Yard 

The establishment of a Government coal storage yard in the 
District of Columbia marks a distinct epoch in coal storage. The 
reasons for this establishment and a description of the plant are as 
follows: 

The Sundry Civil Act, carrying appropriations for the fiscal year 
from July 1, 1918, to June 30, 1919, inclusive, which was approved 
by the President on July 2, 1918, directed the Secretary of the Interior 
to establish under the Bureau of Mines a storage and distributing yard 
for the handling of fuel for the use of and delivery to all branches of 
the Federal service and the municipal government in the District of 
Columbia and immediately adjacent thereto, and authorized him to 
select, purchase, contract for, and distribute all fuel required by the 
said services. 

This establishment was brought about as a result of the lack of 
adequate means for receiving and distributing coal for the use of the 
Government in Washington. On account of this lack of equipment, 
the Government was greatly handicapped in obtaining an adequate 
fuel supply for its buildings during the previous winter when coal 
production was at a low ebb and when transportation conditions, ad¬ 
versely affected by unprecedented weather conditions, made it im¬ 
possible to get a daily supply into the city. 

The annual requirements of the Departments supplied with fuel 
under the above legislation are approximately 400 000 tons of anthra¬ 
cite and bituminous coal per year. Most of the power and heating 
plants in which this coal is consumed do not have bunker capacity for 
more than a week or ten days’ supply. Therefore the provision of 
sufficient storage space for coal to take care of all of the requirements 
of the Department for a period of a month seemed essential to the 
securing of a regular daily supply of fuel to the points of consumption. 

There are periods in the middle of winter when the daily require¬ 
ments for delivery of coal by trucks amount to from 2000 to 2500 
tons. It seemed necessary, therefore, to provide some means of han¬ 
dling this large daily consumption in the middle of winter, with a min¬ 
imum increase in the regular working force of the yard. The Stuart 



Fig. 55. Government Coal Storage Plant, Washington, D. C. (Stuart System) 





























































no 


ILLINOIS ENGINEERING EXPERIMENT STATION 


System of storage and distribution, with certain modifications to suit 
the conditions peculiar to the job, was selected. 

Coal storage in this yard began about June 1, 1919. The storage 
capacity is about 30 000 tons with a capacity in the distributing bins 
of about 1200 tons; the plant is so arranged that the distributing 
equipment is not dependent for its continuous activity upon the 
amount of coal coming into the yard, and, on the other hand, the labor 
force in unloading incoming coal is not dependent upon the immediate 
ability of the distributing equipment to handle it. 

The general arrangement and operation of the plant is shown in 
Fig. 55. The coal is received in self-clearing hopper-bottom cars which 
are dumped into a track hopper from which the coal is fed to conveyor 
No. 1, running in an underground tunnel, which has a capacity of 350 
tons of coal per hour. The coal is weighed while in motion on the con¬ 
veyor by means of a Messiter Conveyor Scale with a guaranteed 
accuracy of one-half of one per cent, so that the carloads of coal can 
be weighed separately. This conveyor delivers the coal to an inclined 
Conveyor No 2, shown at the left, which in turn delivers it to conveyor 
No. 3 (see also Fig. 56), running on the surface lengthwise of the yard. 
A stacker (see also Fig. 57) runs on the track and spans conveyor No. 
3. It is of the portable conveyor type receiving the coal from con¬ 
veyor No. 3 at any point and delivering it either to the coal bins for 
truck loading (See also Fig. 58) or to any storage pile alongside the 
conveyor. When the amount of coal received just equals the amount 
needed for distribution, the coal is conveyed directly to the distributing 
bins which are self-clearing and from which the coal flows without re¬ 
quiring any labor other than that of opening the valves directly into 
the trucks for distribution. If the amount of coal received in any one 
day is greater than can be placed in the distributing bins, the stack¬ 
ing machine which normally delivers to the bins can be withdrawn 
under its own power to any point in the storage yard where the surplus 
amount of coal received during the day can be put into storage. If, on 
the other hand, more fuel is required for distribution on any given 
day than is received in cars, the necessary amount of coal can be re¬ 
claimed from the storage space by means of a locomotive crane, which 
lifts the coal into a traveling hopper, whence it is fed to conveyor No. 
3, and thence to the stacker and distributing bins as in normal opera¬ 
tion. 

Fig. 58 shows a general view of the office and bins from which the 
trucks used for distributing the coal are loaded. Mr. George S. Pope 



Fig. 54. Portable Conveyor Supported by Overhead Trolley 













Fig. 56. Surface Conveyor, Government Coal Storage Plant, 

Washington, D. C. 

T 


Fig. 57. Stacker, Government Coal Storage Plant, Washington, D . C. 














Fig. 58. Distributing Bins and Office, Government Coal Storage Plant, 

Washington, D. C. 












BITUMINOUS COAL STORAGE PRACTICE 


115 


of the United States Bureau of Mines, who has charge of this storage 
plant, reports as follows in regard to the experiences at this plant. 

Four kinds of coal were placed in storage as follows: 

New River coal from various mines; coal from a mine operating 
the Upper Kittaning or C Prime bed, Somerset County, Pennsylvania; 
coal from a mine operating the B or Miller bed, Cambria County, 
Pennsylvania ; and coal from several mines in Tucker County, West 
Virginia. The New River and Somerset County, Pennsylvania, coals 
were placed in storage in June and July, and the Cambria County, 
Pennsylvania, and Tucker County, West Virginia, coals in September 
and October. 

With the New River coal three or four spots indicated heat by 
vapors being given off, but this was easily overcome by shoveling out 
the coal and in no case was it necessary to dig down more than five 
feet. The warm coal was spread over the outside of the pile and the 
heat subsided. This heating took place within a month or six weeks 
after the coal was put in storage and since then there have been no 
further indications of heating in the New River coal. There have 
been no indications of heating in the Somerset County, Pennsylvania, 
coal. Within two or three weeks after it was put in storage the Cam¬ 
bria County, Pennsylvania, coal showed signs of heating as indicated 
by vapors rising from different points. Attempts were made to over¬ 
come this heating by having men shovel the hot spots out as was done 
with the New River coal, but as this superficial treatment was not 
effective, the pile was dug into with the locomotive crane and the coal 
used at once. In a pile containing about one thousand tons of this 
coal the heating became so serious that arrangements were made to put 
in several tractor cranes but these were not necessary. The heating 
seemed to be at different points throughout the pile and some coal 
on the verge of flaming was found within two or three feet of the sur¬ 
face at the top and sides as well as throughout the interior. One spot 
where the coal had actually burned and where ashes were found was 
next to the concrete floor. 

The Tucker County, West Virginia, coals showed some indications 
of heating and w r ere given the same superficial treatment as the New 
River coal, but this coal as well as all of the Cambria County, Penn¬ 
sylvania, coal was moved out of storage during the coal stiike. The 
Somerset County, Pennsylvania, coal pile was practically untouched 
and about one-half of the New River coal was removed. 


116 


ILLINOIS ENGINEERING EXPERIMENT STATION 


INI r. Pope describes the several coals as follows : 

i ‘ The Somerset County, Pennsylvania, coal is about the lumpiest we have, 
the New River being second, the Cambria County, Pennsylvania, third, and the 
Tucker County, West Virginia, fourth. The Cambria County, Pennsylvania, coal 
has a slightly higher sulphur content than the others, its content averaging about 
two per cent. ’ ’ 


The following analyses of these coals are taken from Bulletin 119, 
United States Bureau of Mines. 



New River, 
Shipments on 

28 Contracts 

Somerset County, 
Pa., Shipments 
on 1 Contract 

Tucker County, 

W. Va., Shipments 
on 5 Contracts 

Cambria County, 
Pa., Shipments 
on 16 Contracts 

Moisture. 

1.21- 3.49 

3.52 

2.77- 4.09 

1.82- 2.89 

Volatile. 

16.61-23.56 

15.43 

17.39-24.29 

19.56-22.71 

Fixed Carbon . . . 

70.03-78.82 

75.89 

66.52-72.47 

69.81-73.75 

Ash. 

4.55- 6.57 

8.68 

7.87-10.14 

6.30- 9.11 

Sulphur. 

'0.65- 1.00 

0.92 

1.02- 1.18 

1.77- 2.13 


The New River and Somerset County, Pennsylvania, coals were 
piled to a height of sixteen to eighteen feet but, by moving the stacker, 
the coal was piled in laj^ers in a number of small cones so as to avoid 
the segregation that would result if the coal was dumped at one point 
and a large cone thus allowed to build. The Cambria County, Penn¬ 
sylvania, and the Tucker County, West Virginia, coals were similarly 
piled twenty-five feet high in places. 

Erie Railroad Storage Plant 

Pig. 59 shows a plan of an extensive storage plant of the Erie Rail¬ 
road located at Buffalo, New York. It comprises a typical installa¬ 
tion of the Stuart System of belt conveyors built by the International 
Conveyor Corporation. # The storage piles are at some distance from 
the coal pockets and across the railroad yard. Two tracks for incoming 
coal are parallel to the two storage piles, each of which is to hold 15 000 
tons, the total of 30 000 tons representing a month’s supply for the 
coal pockets. Of these two tracks, one is for loaded and the other for 
empty cars. The coal is dumped through a track hopper into the boot 
of conveyor No. 1 which delivers it to a hopper at the top of the con¬ 
veyor from which it is delivered, in turn, to belt conveyor No. 2, whicii 
runs lengthwise of the storage yard. On each side of the trough in 

* A detailed description of the plant will be found in the Railway Ajre, Vol. 65, No. 14, 
p. 615. 

















BITUMINOUS COAL STORAGE PRACTICE 


1 17 



which conveyor No. 2 runs there is a rail; upon this rail runs a stacker 
which thus spans conveyor No. 2 (See Figs. 60 and 61). This stacker 
is essentially a movable tripper through which the conveyor belt runs 
and by means of it the coal can be delivered at any point along the 
travel of the conveyor belt. The stacker delivers to a loader running 
on the same track as the stacker which consists of a conveyor belt 
mounted on an arm that is pivoted so as to have a lateral swing of 180 
degrees and a vertical movement so that the coal can be delivered with 
a minimum drop. The stacker in Figs. 59 and 60 is shown delivering 
to conveyor No. 3, which carries the coal to the coal pockets. For stor¬ 
ing coal the stacker delivers into the storage piles. 

To take coal from storage a reclaimer is used. This works on the 
same track as the stacker and loader, and is shown in Fig. 61. Like the 
loader, it is a belt conveyor operating on an arm that is pivoted on a 
platform and has a wide lateral swing. One end rests on the ground 
and a plow at the end of the arm is forced into the toe of the coal pile; 
the coal falling on the belt is then delivered through a hopper to con¬ 
veyor No. 2 from which it is passed on to the coal pockets as previously 

described. 



















































































118 


ILLINOIS ENGINEERING EXPERIMENT STATION 


If the coal arrives at the yard faster than it is used for current 
coaling, it is placed in storage, but otherwise it goes directly from the 
track hopper through Conveyors 1, 2, and 3 to the pockets. 

34. Monorail System .—The Godfrey Conveyor System for coal, 
ashes, etc., illustrated in Fig. 62, consists of a one-ton bucket or skip 



T»OLL«V 


RCCLAIMINO 
, BUCKET 


Boiler Mouse 



inf 

W\ 

LmJ 

, , , 7 


Fig. 62. Godfrey Conveyor System for Storing and Handling Coal 


traveling on a suspended monorail or wire rope. The bucket is loaded 
by gravity at the side of the unloading railroad track. The full bucket 
is hoisted by means of a small electric hoist to the level of the sus¬ 
pended monorail or wire rope along which it is pulled by means of an 
endless rope operated by the electric hoist. When the dumping point 
is reached the bucket may be lowered to such a point that the break¬ 
age of coal in dumping will be small. The installation is designed to 
meet the needs of plants using from 15 to 150 tons per day and the 
manufacturers claim that one man can deliver about 30 tons of coal 
per hour either to storage or to the boiler plant. To reclaim the coal 
from storage, it may be shoveled into the bucket by hand, or a reclaim¬ 
ing bucket may be used. 

A monorail system of storing and reclaiming coal as used by the 
American Spiral Pipe Works of Chicago is shown in Fig. 63. A steel 
structure supports a single rail upon which operates the support for 
a movable clam-shell bucket. The coal is both stored and reclaimed 
with the same device, but the capacity is limited by the fixed position 
of the monorail, and the coal piled with this device forms a conical pile 
with the resultant segregation of sizes and increased liability to spon¬ 
taneous combustion. 






























































Fig. 60. View of Coal Storage Plant of the Erie Railroad, Buffalo, New 
York, Showing Conveyor No. 2 and Stacker Delivering to Conveyor No. 3 



Fig. 61. View of Coal Storage Plant of the Erie Railroad, Buffalo, New 
York, Showing Loader at End of Conveyor No. 2 























Fig. 63. Monorail System for Storing and Reclaiming Coal 








bituminous coal storage practice 


121 


A similar bucket storage system lias been built by the Lidgerwood 
Manufacturing Company, for the Galveston Coal Company, for un¬ 
loading coal from steamers and conveying the coal to a storage pile. 
Fiom the storage pile the coal is reclaimed and loaded into barges and 
railroad cars. 1 he system consists of a self-filling bucket of the grab 
type which is moved along a fixed overhead track by means of rope 
haulage. The capacity of the Galveston installation is about 700 tons 
per day. 


35. Cableway System .—The cableway system for storing and 
reclaiming coal consists of a hoisting and a conveying device, the latter 
operating over a single span cable supported by a tower at each end. 
The load may be taken from any point, conveyed in either direction, 
and deposited wherever desired along the line of the cableway. 

The cableways are built in various types to meet different require¬ 
ments, (a) with both towers fixed, as is Fig. 64; (b) with both towers 




Fig. 65. 



Cableway System for Handling Coal — Both End Towers Movable 



















































122 


ILLINOIS ENGINEERING EXPERIMENT STATION 




Fig. 66. Cableway System for Handling Coal — One End Tower Fixed, 

the Other Movable 

traveling on parallel tracks, as in Fig. 65; (c) with one tower fixed 
the other traveling on a circular track about it as in Fig. 66. 

36. Automatic Dump Car Storage .—The coal storage plant of 
the Karm Terminal Company at Bridgeport, Connecticut, installed by 
the Bergen Point Iron Works of Bayonne, New Jersey, is shown in 
Fig. 67. The coal is unloaded from barges by cranes as shown and 
dumped into automatically dumping electric cars which discharge 
either into a storage pile, into railroad cars, or into a coal pocket. 
Coal is reclaimed from the storage pile by another set of electric cars 
running through tunnels underneath the pile. These cars either take 
the coal to a loading pocket for loading automobile trucks or dump the 
coal into railroad cars, about twenty of which can stand underneath 
railroad viaducts. These railroad cars can all be loaded without being 
moved, as the small car can be made to dump automatically at any 
point. 

37. Cristobal and Balboa Coaling Stations .—The coaling stations 
located at Cristobal and Balboa at the two ends of the Panama Canal 
are shown in Figs. 68 and 69. These were built by the Bergen Point 
Iron Works of Bayonne, New Jersey, and represent advanced practice 
for the handling of coal. The combined storage capacity of the two 
is 700 000 tons. At Cristobal Station 1200 tons per hour can be 










Fig. 67. Coal Storage Plant of the Karm Terminal Company, Bridgeport, Connecticut 
















Fig. 68. The Cristobal Coaling Station, Panama Canal 
















Fig. 69. Balboa Coaling Station, Panama Canal 








BITUMINOUS COATj STORAGE PRACTICE 


127 


unloaded and 2400 tons per hour reloaded. The storage plant includes 
both underwater and dry storage. The general layout of the plant is 
shown in the photographs; a number of articles descriptive of the de¬ 
tailed construction have been published.* 

For the unloading and stocking, coal is taken from colliers or 
barges by unloaders equipped with 2^-ton buckets which have a rated 
capacity of 250 tons per hour. The coal is taken from the un-loaders 
to the dumping point bj r cars. It is reclaimed from storage by re¬ 
claiming bridges, each of which is equipped with a 5-ton bucket, having 
a rated capacity of 500 tons per hour. The total handling capacity at 
Balboa is only half that at Cristobal. 

38. Suction Conveyor .—An application to coal storage purpe es 
of the suction conveyor for handling coal and ashes at a power plant 
as used by the Pierce-Arrow Motor Car Company at Buffalo, New 
York, is shown in Fig. 70. Coal is taken from a track hopper by suc¬ 
tion to a 100-ton coal tank from which it is delivered by motor-driven 
cars to the bunkers above the boilers. As is shown in Fig. 70 a reserve 
storage of 3000 tons is provided at one end of the plant by continuing 
the track and delivering coal from the coal tank in the motor driven 
cars to a storage pile instead of to the bunkers. Coal from the storage 
pile is reclaimed by permitting it to run into an underground reclaim¬ 
ing duct from which it is sucked into the 100-ton coal tank. At this 
plant bituminous screenings are used. 


39. Mine Storage .—At Aldrich, Alabama, the Montevallo Mining 
Company operates a longwall mine with convict labor. In order that, 
the mine might be operated six days a week with a variable supply of 


* “Coaling and Supply Depots at Panama.” Black Diamond, Vol. 49, No. 25, p. 20, 
Dec. 21, 1912. 


“Coaling Plants at Panama Canal.” Coal Age, Vol. 3, p. 481, 1913. 

“Panama Canal’s Big Coaling Station.” Coal Trade Bulletin, Vol. XXXV, p. 31, 
Oct. 2, 1916. 


“Coaling at the Panama Canal—Cristobal,” by F. J. Warden-Stevens. 


Colliery Guardian, 


Vol. CXII, p. 745, Oct. 20, 1916. 

“Coal at the Panama Canal—Balboa,” by F. J. Warden Stevens. Colliery Guardian, Vr 
CXII, p. 789, Oct. 20, 1916. 


Oct. 


“Panama Canal Coaling Plants.” Coal Trade Bulletin. Vol. XXXVI, p. 43, Apr. 2, 

“Uncle Sam’s Great Storage Docks.” (Panama). Coal Trade Bulletin. Vol. 39, pp. 
15, 1918. 


1917. 

37-38, 



128 


ILLINOIS ENGINEERING EXPERIMENT STATION 



Fig. 70. Suction Conveyor Coal Storage Plant of the Pierce-Arrow 
Motor Car Company, Buffalo, New York 

railroad cars, a storage method was introduced. The general arrange¬ 
ment is shown in Fig. 71. Railroad cars loaded at the tipple are run by 
gravity several hundred feet to a suitable storage ground where the 
coal is shoveled out of the cars by hand labor or drawn from the bottom 
with hopper-bottom cars. When as much coal as possible has been 
stored in this way a wall is built of the larger lumps carefully piled 
along the railroad tracks. Planks placed on top of these walls and on 
top of the gondolas furnish a runway for the wheelbarrows which are 
loaded from the cars and dumped at the edge of the pile. The total 
capacity is about 20 000 tons and the cost of unloading approximately 
eleven cents per ton. The coal is reclaimed into one-ton mine cars 
running on a track at the foot of the storage pile as shown. These 
cars are pulled by a gasoline locomotive and hoisted three at a time up 
an incline into a revolving dump where the trip of three is emptied 
without uncoupling. The cost of reclaiming is ten cents per ton. 

These costs will probably be decreased by the use of another rotary 
dump instead of so much hand-labor and if side-hill storage were used 
the cost of loading into the one-ton cars could be saved. 

A belt conveyor has been built at Fairpoint, Ohio, by the Roberts 
and Schaefer Company of Chicago for the Clarkson Coal Mining Com¬ 
pany of Cleveland, Ohio. This belt conveyor is supported on a trestle 















































































































Fig. 72. Underwater Coal Storage Plant of the Standard Oil Company, 

Whiting, Indiana (100 000 Tons Capacity) 


ig. 71. Storage System Used by the Montevallo Mining Company, 

Aldrich, Alabama 


































BITUMINOUS COAL STORAGE PRACTICE 


131 


for storing the slack, which is taken from beneath the screens, and by 
means of a tripper is dumped on the ground beneath the trestle. The 
coal is reclaimed with a locomotive crane. The plant lias a capacity 
of 40 000 tons and 300 tons per hour can be handled. Lump, three- 
quarter, mine-run, and slack can be stored. The plant is intended 

for storage purposes when the car supply is low so that a full day can 
be run at the mine. 


40. Underwater Storage .— u 

Duquesne Light Company Storage Plant 

The Duquesne Light Company, Pittsburgh, Pennsylvania, com¬ 
pleted during the fall of 1917 a large reinforced concrete storage basin 
at the Brunot Island power plant. # 

The storage basin which is adjacent to the power plant, and be¬ 
tween it and the main channel of the Ohio River, is 791 feet long, 153 
feet wide, and 25 feet, 6 inches deep, the side and end walls sloping at 
an angle of 45 degrees. The basin has a capacity of 100 000 tons of 
submerged coal and 150 000 tons with the coal piled above the water¬ 
line. The side and end walls of the basin taper from 18 inches at the 
bottom to 8 inches at the top. 

As the bottom of the basin is below the normal river level, special 
provision had to be made for the lifting pressure that would be exerted 
on the bottom of the basin at high water stages, the soil being coarse 
gravel and very porous. The bottom which is 18 inches thick isf/made 
of 30 main reinforced concrete slabs each 51 feet square. These slabs 
rest on reinforced concrete curbs the bases of which are 4 feet square 
and 12 inches thick; the bridge extending up from the base is 15y 4 
inches high and 6 inches wide. These curbs, besides supporting the 
bottom, also allow for expansion and contraction of the concrete slabs. 
All joints are filled with pitch. The plant condenser-water discharge 
duct which is constructed of concrete divides the basin into two sec¬ 
tions. The fact that the top of the duct is 7i/ 2 feet above the concrete 
bottom permitted one-half of the basin to be used while the other half 
was being constructed. 

Water for flooding the basin is admitted through 12-inch filling 
holes and is supplied by one of the plant condenser circulating pumps, 
equipped with a discharge pipe for this purpose. Four 18-inch 


* Power, page 651, Nov. 13, 1917. 



132 


ILLINOIS ENGINEERING EXPERIMENT STATION 


independent drain pipes which extend to the river are each equipped 
with a gate and a check valve, and with a by-pass around the latter. 
The basin can be drained by opening the gate valves. This arrange¬ 
ment permits the automatic flooding of the coal basin with river water 
to relieve the upward pressure on the concrete bottom. Should the 
river rise much above normal, water will flow into the basin to a height 
corresponding to that of the river. When the river subsides the water 
may be drained from the basin if desired. At the present time no 
figures with respect to the operating cost of the storage basin are avail¬ 
able. 


Underwater Pit of the Standard Oil Company, 

Whiting, Indiana* 

Figs. 72 and 73 show an underwater storage pit built by the 
Great Lakes Dredge and Dock Company of Chicago, Illinois, for the 
Standard Oil Company about two miles south of the shore of Lake 
Michigan at Whiting, Indiana. This storage pit has a capacity of 
100 000 tons. 

The storage basin consists of a pit 1000 feet long, 202 feet wide, 
and 28^ feet deep below yard rail level and 24% feet, deep below 
ground water level. The pit is enclosed by a heavy wooden sheet-pile 
dock construction below water level, capped with concrete above water 
level. There are four lines of standard gauge railroad track trestle 
running longitudinally through the pit and four lines on each side 
of the pit. 

The pit was excavated with a 15-inch hydraulic suction dredge, 
which was hauled overland a mile and a half to the site; advantage 
was taken of the marshy conditions to excavate a sufficiently large area 
in which to float the dredge. The excavated material was discharged 
through pipes at a point 1000 feet away from the pit and the run-off 
water carried back to the pit through trenches; thus a sufficient supply 
of water was insured to keep the dredge afloat. Wakefield sheet-piling 
and dock-piling were then driven by means of two floating pile drivers, 
built on the site, and the concrete mass surrounding the pit at the 
water line was placed, special concrete mixers being mounted on rail¬ 
road flat cars. The bottom of the pit was leveled off with the hydraulic 
dredge by means of a special mouth-piece, so that no point was more 
than six inches above or below grade. After the dredge had leveled off 


* See also Circular No. 6, p. 103. 



BITUMINOUS COAL STORAGE PRACTICE 


133 




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OWV.C ‘sa/fc/sQZ 

-///S' JOLjOUty 








































































































































































134 


ILLINOIS ENGINEERING EXPERIMENT STATION 


the bottom, a drag was used consisting ot* a heavy horizontal 12 feet by 
1 foot timber fastened to a pile driver. 

The concrete boor, one foot in thickness was placed in about 25 
feet of water over the entire floor area of 1000 feet by 202 feet, by 
means of a special tremie device, patented by the Great Lakes Dredge 
and Dock Company. By using this device, it was possible to place the 
concrete under pressure and to spread it uniformly over the bottom, so 
that no point was more than three inches off grade. 

The following advantages are claimed for this form of pit con¬ 
struction : 

1. Lower cost than for all concrete or wood-and-concrete 
construction. 

2. Lower cost of unloading coal by dumping from 
trestles and from tracks along the sides of the pit than by 
using grab-buckets operated by a bridge or crane. The bulk 
of the unloading cost consists in dumping the cars (either bot¬ 
tom or side dump) from the trestles or from the side of the 
pit, leaving a very small portion to be unloaded with yard 
cranes. 

This method permits the use of different sizes of locomotive cranes 
where they are available around any plant. 

By means of the four tracks running through the pit and those 
on each side, six trains, of at least twenty 50-ton coal cars can be un¬ 
loaded or loaded simultaneously. 

The four tracks in the pit and those along each side give a track¬ 
age length of practically two miles for rail storage purposes; in other 
words, little ground space is lost by installing one of these pits in this 
manner. In fact, any switch yard can have an underwater coal stor¬ 
age pit without the acquisition of more land. 


135 


BITUMINOUS 


COAL STORAGE PRACTICE 


APPENDIX I. 

Questionnaire A 

1. AVhat kind of coal was stored? . 

2. What size of coal was stored? . 

3. Was all of the coal stored of same size and kind? . 

4. What amount of coal was stored? . 

5. State from what mining district and if possible from 

what mine the coal came:. 

6. Size of pile: Depth.; Length.; Breadth 

7. Describe the method of unloading and storing:. 


8. Was coal unloaded, by crane, drop bottom car, hand? 

9. What trouble have you had from fires 

in your coal pile? . 

10. How much of the coal was destroyed by fire? . 

11. What in your opinion was the cause 

of the fire? . 


12. What evidence have you upon which 

to base this opinion? . 

13. How long had the coal been in storage when 

the fire was observed? . 

14. Was the coal actually ablaze or only smoking? . 

15. Was the temperature taken?.What was it? . . . 

16. Where in the pile did the fire start? . 

17. How was the fire controlled or extinguished? . 

18. Was any attempt made to ventilate the pile; if so, how? 

19. Was there any damage to adjacent structures? . 

20. Information furnished by:. 


(Ofiicial title and Company) 


(Address) 

General Remarks: 


Please use reverse side of this sheet for any general remarks 

and suggestions. 

Questionnaire B 

Please answer the following questions and mail your answers direct and as 
soon as possible to Professor H. H. Stoeb, Department of Mining Engineering, 
University of Illinois, Urbana, Illinois. 































136 


ILLINOIS ENGINEERING EXPERIMENT STATION 


1. What kind of coal was stored? . 

2. What size of coal was stored? . 

3. What amount of coal was stored? . 

4. State from what mining district and 

if possible from what mine the coal came:. 

5. The size of pile: Depth.; Length.; Breadth 

6. Describe the method of storing:.. 


7. Have you had any difficulty 

from fires in your coal pile? . 

8. How much, if any, of the coal 

was destroyed by this fire? . 

9. What in your opinion was the cause of the fire? 


10. What evidence have you upon 

which to base this opinion? .. 

11. How long had the coal been in storage 

when the fire was observed? . 

12. Was the coal actually ablaze or only smoking? . 

13. Where in the pile did the fire start? . 

14. How was the fire controlled or extinguished?. 

15. Was any attempt made to ventilate the pile; if so, how? 

16. Was there any damage to adjacent structures? . 

Information furnished by: 


(Company) 


(Address) 


(City and State) 

For general remarks use back of this sheet. 

Data Sheet 

Date. 

Name and address:. 

Party interviewed:. 

Size and kind of coal:. 

Mine or district :. 

Name of shipper:. 

Is COAL CORRECT SIZE? . 

Amount of sulphur:. 

Method of piling :. 

Tonnage and dimensions of pile:. 

How LONG IN STORAGE? . 





































BITUMINOUS COAL STORAGE PRACTICE 


137 


Ventilated:. 

Where did fire start ? .. 

Was water used? . 

Picture:. 

HOW WAS FIRE HANDLED? 

Probable cause of fire :. 

REMARKS:. 









138 


ILLINOIS ENGINEERING EXPERIMENT STATION 


; APPENDIX II 

Railway Administration Storage Circular 

The following circular of instructions for the storage of coal was 
sent by the government to all railroads in the United States. It is, 
undoubtedly, the most comprehensive effort to safeguard and stimu¬ 
late the storage of coal ever made in an industry. 

The Storage of Coal 

To Operating Officers in Charge of Coal Storage: 

The standing committee on the storage of coal, appointed by the Interna¬ 
tional Railway Fuel Association, has made a number of recommendations which 
are contained in the transactions of the association for the year 1909 to 1917, 
inclusive. 

An exhaustive study of the storage of bituminous coal was also made by 
H. H. Stoek, professor of mining engineering of the University of Illinois, Ur- 
bana, Ill., and published March 4, 1918, in Circular No. 6 of the Engineering Ex¬ 
periment Station of that university. 

A further circular covering additional features in the storage of bituminous 
coal will be published and ready for general distribution within a few months. In 
the meantime Professor Stoek is preparing a paper on the storage of bituminous 
coal to be read at the eleventh annual meeting of the International Railway Fuel 
Association convening in Chicago in May next. 

From this information, and that which lias been furnished by the United 
States Railroad Administration, certain suggestions have been gathered covering 
the proper method of storing railroad coal which, if applied, will assist in keep¬ 
ing the cost of storage to the minimum, and will result in greatly reducing or 
entirely eliminating the hazard caused by spontaneous combustion. 

From necessity no general rule can be made which will fit the various coals 
stored in the different sections of the country, and railroad officials in charge of 
this work will be compelled to exercise a reasonable measure of discretion in 
carrying out any recommendations of a general character that may be made. 

Why Railroads and Other Consumers Should Store Coal 

1. To insure an ample supply for locomotives and miscellaneous steam pur¬ 
poses during period of reduced delivery occasioned by cessation of water-borne 
traffic, mine strikes, extremely rigorous winter weather, periods of serious car 
shortages, etc. 

2. Ho that a partial equalization of the coal-car supply may be made. The 
excess demand for railroad and commercial coal during the fall and winter sea¬ 
son, accentuated by a decreased daily car mileage, invariably leads to a car 
shortage during that period, with a resulting surplus during the summer season, 
when coal is ordinarily stored. 


BITUMINOUS COAL STORAGE PRACTICE 


139 


3. The cost of transporting railroad coal during the summer season is estim¬ 
ated as not exceeding CO to 65 per cent of the cost of such movement during the* 
period of extreme winter weather, during which time if the carrier is relieved, if 
only in part, of the transportation of railroad coal, the locomotives, cars, and coal 
thus made available can be diverted to commercial consumers, with resulting re¬ 
venue advantage. 


How to Store Coal 


The actual work incident to the storage of railroad coal should only be under¬ 
taken after a study of the subject has been made by some responsible official, who 
should, after conferring with the proper representatives in charge of purchase, 
transportation, and maintenance, formulate such definite plans as will insure the 
full co-ordination of every man responsible for any portion of the work to be 
done; to this end the following points should be given careful consideration: 

( a) Determine the amount of coal which should be stored, beginning May 1, 
ending August 31, except in the case of water-borne coal, where the storage period 
will be governed by the navigation season. The rate of storage daily and weekly 
should be prescribed in order to prevent an under or over supply at the storage 
station. Storage points remote from the source of supply should be given pre¬ 
ference. 


(&) As far as possible, avoid purchasing coal for storage that bears the re¬ 
putation of firing when stored. 

(c) Store screened lump coal where such is obtainable, 4-inch or 6-inch lump 
preferably, the portion passing through the 4-inch or 6-inch screen openings to 
be used for current consumption during the storage period. Coal placed in in¬ 
dividual storage piles should come from as few mines as possible. In no case mix 
coal from different districts or from different seams located within the same 
district. 


( d ) Before undertaking storage select a suitable location as near as possible 
to the point of consumption, avoiding hillsides, rough ground, and soft, wet, boggy 
ground in particular. The storage location should be thoroughly cleaned of all 
refuse matter, giving particular attention to the removal of vegetation, wood, 
discarded waste, old clothes, or other similar combustible matter which would 
assist in starting stock pile fires or would depreciate the value of the coal when 
loaded out. Do not pile above a steam pipe, over a sewer trap, or against a hot 
wall. Positive provision should be made for draining the ground so that watci 
may not accumulate under the pile. 

( e ) it is now well established that coal fires spontaneously by the oxidation 
of the fin§ particles, which present the maximum surface for the air to act upon, 
well-screened coal carefully piled seldom firing, for the reason that a minimum 
surface is subjected to oxidation, the openings between the lumps admitting of 
any heat engendered passing off. Fires usually start in piles where the coal is 
more or less separated in coarse and fine strata, the air entering through the 
coarser strata acting on the finer portion, which is too dense to admit of the heat 
created passing off with sufficient rapidity to prevent firing. Fine coal should be 
invariably stored by itself and in such a way as to exclude as far as possible the 

air from entering the pile. 


140 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Slack coal has been stored successfully to a height of 8 or 10 feet by packing 
it as hard as possible, covering the surface with the finer portion in such manner 
as to as nearly as possible exclude air and water. 

Water entering the bottom of a storage pile is exceedingly dangerous from a 
firing standpoint. 

Method of Unloading 

(1) No plan covering the unloading of storage coal should be put into effect 
without due consideration to the work of reloading same, bearing in mind that 
in the event of spontaneous combustion the portion firing must be removed 
quickly. 

Where locomotive cranes with clam-shell buckets are available, two parallel 
tracks, located at from 16 to 20 feet centers, should be laid down on high level 
ground cleared of all refuse and combustible matter. The loaded cars are placed 
on one track and unloaded by a crane operating on the parallel track, the coal 
being placed in a pile alongside the crane. The position of the cars and crane is 
reversed wfith the completion of the first pile. The width of the pile depends on 
the radius of the boom travel, and its maximum height is determined by the width 
of the base and the flow line of the coal, not exceeding, however, a total of 20 
feet. The height should be decreased in the case of coals that have been known 
to fire easily. The tracks should remain in position for the quick removal of coal 
that may become overheated and for the subsequent reloading of the coal stored. 

(2) Extensive investigation has shown that many fires have occurred in stor¬ 
age piles where a separation of the coarse and fine coal was made, by dumping 
the coal as unloaded, on the same spot, or along the center line of the pile, the 
coarse coal rolling down to the side, the fine coal accumulating at the center or 
axis of the pile; the air entering the pile through the coarser portion and acting 
on the centrally located mass of fine coal producing heat, which, on account of an 
insufficient air circulation, is not carried off with sufficient rapidity to prevent high 
temperatures and spontaneous combustion. This hazard will be very materially 
lessened if the clam-shell is lowered to a point just above the surface of the pile 
before the contents are dumped. A layer of coal 2 feet in height should be laid 
down to the full width of the base of the pile and over the entire length of same, 
the second and succeeding layers, each 2 feet in thickness, to be laid down in like 





Laver NS5 



.fkW* *?«4*Z* Layer 


Fig. 74. Method of Building Pyramidal Pile in Layers* 


£ 


£ 



* Level of storage pile raised two feet at a time the full length of pile, by lowering the 
clam-shell to a point just above the surface of the pile before discharging contents. 























BITUMINOUS COAL STORAGE PRACTICE 


141 


manner. This method of unloading will eliminate the accumulation of broken fine 
particles in the center of the pile, and in addition, give the coal a limited op¬ 
portunity to season before being covered up by the succeeding layer. A sketch 
showing a cross section of a pile so laid down is shown herewith. 

(o) Where locomotive cranes are not available, coal from necessity is fre¬ 
quently stored by unloading self-clearing cars placed on a track on the top of 
the pile, the track raised from time to time on the coal. This arrangement has 
the disadvantage of causing an accumulation of crushed coal in the center of the 
pile, with lumps on the outside as referred to in paragraph (2). Where it is 
necessary to employ this method of unloading and after the pile is completed, 
the track should be moved from the top of the pile to the surface level and parallel 
to the storage pile, thus making provision for the quick removal of any portion 
that may fire by using the standard railroad non-revolving steam shovel, the 
American type railroad ditcher, or locomotive crane, for reloading the coal either 
in case of emergency heating or for current use. Coal so stored should not be 
piled to a height exceeding 12 to 15 feet, and the reloading tracks should be 
maintained readily accessible for prompt use in event of spontaneous firing, and the 
shovel, crane, or ditcher kept readily accessible and always in condition to be used. 

Where mechanical means are employed for spreading coal so unloaded, a 
standard railroad ballast spreader is preferable to the track tie dragged through 
the coal underneath a car truck as commonly done. 

(4) Trestle storage should be restricted to the handling of coal of established 
reputation for safe-keeping. The fire hazard attendant on placing storage coal 
around the wooden trestle, plus the cost of construction of same, and the difficulty 
of handling, makes this method of storage inadvisable. 

(5) Any attempt toward the storage of coal will prove, at best, only par¬ 
tially successful, unless some one responsible individual is placed in charge of same 
with full authority to co-ordinate the various branches of the purchasing and 
operating departments. A thoroughly competent' foreman should be maintained 
at every storage pile to oversee the storage, to inspect the billing before cars are 
unloaded, to determine the source of supply and the grade of coal furnished, and 
to divert to current consumption cars received of grade or kind other than that 
prescribed. 

(6) After the work of storage is completed the storage piles should be ade¬ 
quately policed to prevent wholesale loss by theft and to insure the detection of 
excessive temperature. It is generally agreed that any method of ventilating stock 
piles heretofore employed is insufficient to safeguard them. Excessive heating is 
easily detected by a careful examination of the pile, using the sense of smell; and 
in addition the inspector should be equipped with a few sharpened steel rods, 
which should be driven into the pile at frequent intervals. Any excess heat gen¬ 
erated may be detected by feeling the rod immediately upon its removal. If a 
hot spot *is found with the rods, the temperature should be carefully watched with 
a thermometer placed inside a pipe driven into the pile at the hot place. 

(7) All coal stored should be picked up and consumed under an established 
schedule and during the period of car and coal shortage, when transpoitation is 

most expensive and the facilities of the carrier are in maximum demand. 

Eugene McAuliffe, 

Manager Fuel Conservation Section. 


142 


ILLINOIS ENGINEERING 


EXI»EKI MENT STATION 


APPENDIX III 
Space Occupied by Coal 

The question is frequently asked: ‘‘ How many cubic feet are 
there in a ton of coal, or how many tons of coal will a railroad car, bin, 
etc., of a given size hold?” 

Knowing the specific gravity of any coal, the weight of a solid 
cubic foot can be readily computed. While such values are useful in 
computing the tonnage of coal in the ground, they are not useful in 
determining the weight per cubic foot of coal broken into commercial 
sizes to be used for fuel or for storage. The weight of coal in com¬ 
mercial sizes depends upon the specific gravity, size, and condition of 
the coal, and the extent to which it has been shaken down or settled. 

The following is a summary of the information available, compiled 
from the literature on the subject and from replies to a questionnaire 
sent to about seventy manufacturers of coal handling machinery, to 
engineers, and to various users of coal. 

A tabulation of the weight of 177 samples of coal from many 
parts of the United States will be found in Technical Paper No. 184 
of the United States Bureau of Mines. These tests were made on 
domestic sizes of coal received in barrels. The coal was shoveled loosely 
into a box measuring 2 ft. by 2 ft. by 2 ft. and leveled off with a 
straight edge. The results show a variation in bituminous coal from 
the several coal districts of the United States as follows : 


Table 18 

Weight of Bituminous Coal in Pounds per Cubic Foot by Districts 


Region 


Weight in Lb. per Cu. 


Appalachian: Pa., W. Va., Md., Va., Ohio, Tenn., 

Ala., and Eastern Ky. 

Eastern Interior Basin: Ill., Ind., and Western Ky. 

Western Interior Basin. 

Rocky Mountain.. 


43 to 57.5 

44 to 55 

45.5 to 59 

44.5 to 52.5 


Ft. 


An average of these same results by states is given in Table 19, 
but for exact information as to coal from any particular district and 
of any particular size, reference should be made to the original paper 
as the averages given include a variety of sizes. 















BITUMINOUS COAL STORAGE PRACTICE 


143 


Table 19 

\\ eight of Bituminous Coal in Pounds per Cubic Toot by States* 


State 

Number of 
Samples 

Average Weight 
Per Cubic Foot 

Extreme Values 
Per Cubic Foot 

Alabama. 

5 

51.3 

45.5-54 0 

Arkansas. 

4 

53.3 

49.5-59 0 

Illinois. 

14 

48.8 

45.0-55.5 

Indiana. 

9 

46.1 

44.0-49.0 

Iowa. 

2 

47.0 

46.5-47.5 

Kansas. 

2 

52.8 

50.0-55.5 

Kentucky . 

11 

47.2 

43.0-54.5 

Montana. 

2 

52.3 

52.0-52.5 

Ohio. 

4 

47.3 

46.0-49.0 

Oklahoma. 

4 

48.5 

45.5-50.0 

Pennsylvania. 

41 

51.2 

46.5-55.0 

Tennessee. 

9 

57.3 

45.0-51.0 

West^Virgima. 

9 

53.3 

41.0-57.5 

Wyoming. 

4 

48.9 

45.5-52.5 


*United States Bureau of Mines. 


The conclusions reached by the author of the paper are: 

‘ ‘ A study of the foregoing table indicates that heavier weights may be ex¬ 
pected for coals of high fixed carbon content than for those of low. Increased 
ash content seems to lower the unit weight. It is also true, in general, that the 
coals high in moisture are lighter than those low in moisture and the younger coals 
are lighter than the older coals. 

‘ 1 These variables combine in so many ways, however, that it is difficult to 
determine from the data available anything more than a general trend and con¬ 
sequently little use can be made of the knowledge of a change of one or more of 
the variables. ” 

The change in weight due to wetting and shaking down a sample 
are summarized in the same paper as follows: 

“ 1 . Of two samples of any coal that are composed of the same proportions 
of pieces of different sizes, the sample having the higher moisture content will 
usually weigh the more per cubic foot. 

“ 2. A sample of higher moisture content will usually occupy more space for 
the same number of pounds of (dry) coal than will a sample of lower moisture 
content. However, the increase in volume for the wet coal is not as great pro¬ 
portionately as is the increase in weight per cubic foot. 

“3. Coal shoveled loosely into a container will settle appreciably if the con¬ 
tainer is shaken, and the weight per cubic foot will be correspondingly increased. 

< ‘ 4 . Slack coal composed of a mixture of the smaller pieces up to and in¬ 
cluding nut size weighs more than screened nut coal. 

“This last statement coincides with the conclusions drawn from experiments 
with concrete mixtures, which have shown that a much denser mixture can be 
made by using certain proportions of various sized pieces. Pieces of nearly uni¬ 
form size when piled leave about 45 per cent of voids. If these spaces are filled 
































144 


ILLINOIS ENGINEERING EXPERIMENT STATION 


with still finer coal of uniform size the weight of the mass is increased and the 
interstices in the finer coal can again be filled with still finer pieces, resulting finally 
in a dense mass. It is evident, therefore, that the relative proportions of fine and 
coarse material have a considerable influence on the weight per cubic foot of the 
mass. ’ ’ 

Table 20 contains the results of a questionnaire which was sent 
to a number of coal handling machinery manufacturers, engineers, and 
coal users for the purpose of obtaining current practice upon the sub¬ 
ject. It must be remembered in this connection, however, that these 
figures do not represent generally figures based upon tests of actual 
conditions but rather upon current practice, allowing an ample factor 
of safety, as most manufacturers desire to give the customer ample 
capacity so that they may be on the safe side in calculating tonnage 
or space. 


Table 20 

Weight per Cubic Foot of Coal as Given by Manufacturers 


Company 

Kind and 
Size of Coal 

Cu. Ft. 
per Ton* 

Wt. per 
Cu. Ft. 
in Lbs. 

Angle of 
Repose in 
Degrees 

Remarks 



37 



Mine car design. 





Hyatt Roller Bearing Co. . . 

Bituminous. 


52H 


4 4 

Sanford Day Iron Works. . . 

Bituminous 

Mine-run. 

40 



4 4 

Hockensmith Wheel & 

Mine Car Co. 

Bituminous 

Mine-run. 


50 


44 

Atlas Car & Mfg. Co. 

Bituminous 

Mine-run. 

Anthracite. 

40 


40-45 

30-33 

44 

Cherry TYfifi IVTarh. Oo. 


37^ 



4 4 





Lakewood Engineering Co.. 

Loose 

Bituminous. 

Anthracite. 


50 

54-56 

30 

30 

Mine and industrial car 
design. 

Helmick, F., Mach. Co. 


42 


\ aried 
with coal 

Gross ton. Mine car de¬ 
sign. 

Jeffrey Mfg. Co. 

Pocahontas. 
Pittsburgh 
Bituminous. 
Ind. and 111. 
Anthracite. 
Bituminous. 
Anthracite. 

40 

50 

35-3716 

40 

40 

30 

40 

37H 

Practice in building chutes. 

«« <4 <4 44 

44 44 44 ti 

(< 44 44 »4 

Open piles. 

4 4 4 4 

Roberts & Schaefer Co. 

Bituminous 

Mine-run. 

Anthracite. 

Lignite. 

Bituminous. 


50 

57 

45 




30-35 

35-40 


Western Wheeled Scraper 
Co. 

Bituminous 

Slack. 

45 


45 

Ton of 2240 lb. 


*2000 pounds. 












































































BITUMINOUS COAL STORAGE PRACTICE 


145 


Table 20 —Continued 


Company 

Kind and 
Size of Coal 

Cu. Ft. 
per Ton* 

Wt. per 
Cu. Ft. 
in Lbs. 

Angle of 
Repose in 
Degrees 

Remarks 

Robins Conveying Belt Co .. 

lk£ in.-?4 in. 
Nut. 

38 H 
35^ 

52 


Loose. 


t i 

56 


Well shaken down. 




Wood Equipment Co. 

Mine-run to 






Lump. 

35-45 





Large Lump. 
W et mine-run 

55 





30 








United Iron Works Co. 


48 


IK-1 

Kansas Mine-run. 




Bucyrus Co.. . . 


40 


50 

1 X A cu. yd. per ton exca¬ 
vating machinery 




Barber-Greene Co.. . 


40 


45 






Macdonald Engineering Co. 


45 

45 

38 

Practice. 



40 

45 

Average as noted. 




Brown Hoisting Mach. Co.. 

Bituminous. 

40 


1J4 hor. 
to 1 ver. 


Anthracite. 

35 






Wellman-Seaver-Morgan 

Co. 

Bituminous. 

40 




Bituminous 


43-45 



Mine-run. 




R. H. Beaumont Co.... 

Bituminous. 

Bituminous 

40 

50 

Max. Min. 
45 35 



Mine-run. 

Crushed 

Bituminous 



45 35 



Anthracite. 



30 27 



Coke. 



50 40 







Bituminous. 


50 

45 



Anthracite. 


56 

30 







Bituminous. 

40 


35 



Anthracite. 


27 









50 


Bin design. 






Great Lakes Dredge and 
Dock Co. 


40 



Dock and bin design. 


Bituminous. 


50 

35 

General practice. 


A ri thra cite. 


52 

27 

(t 


Coke. 


30 

35-45 

(I 


Bituminous. 

Anthracite. 

Coke. 


50-55 


More exact practice. 



52-55 


i« 



25-32 


« 4 





Watt Mining Car Wheel 
Co. 


40 



Mine car design. 


Bituminous. 

40 


40 



Anthracite. 

36 


30 







Bituminous 

40 


40 

Design for bins and stor¬ 
age. This has been 


Mine-run, 
Lump, Egg, 
and Nut. 
Bituminous 
% in. and 
under. 
Anthracite. 








found to give ample 





capacity under approxi- 


45 


40 

mately the extreme 
conditions. 





37 


27 






3 hillips Mine and Mill 
Supply Co. 

Bituminous 

Mine-run. 


52 

45 

Mine car and small storage 




Bin design. 


*2000 pounds. 























































































































































146 


ILLINOIS ENGINEERING EXPERIMENT STATION 


The Peabody Coal Company uses the following figures in estimat¬ 
ing storage for coal and coke in coal yard: 

Table 21 

Cubic Feet per Ton of Coal* 


Bituminous 


Cubic Feet 
Per Ton 


An 


thracite 


Cubic Feet 
Per Ton 


Pocahontas Lump and Egg 
Pocahontas Mine-Run and Nut 

Pocahontas Slack. 

Hocking. 

Screenings. 

Indiana Lump. 

Mine-Run. 

Smithing. 

Quaker Egg and Nut. 

Quaker Lump. 

Acorn Lump. 

New Era. 

No. 3 Washed Nut. 

Wasco Lump. 


35.5 

36. 

35. 
41. 

40. 

41. 

36. 
43. 
40. 
38. 
40. 
38. 

42. 
40. 


Chestnut. 

34 

Range. 

35 

Small Egg.... 

35 

Large Egg.... 

36 

Pea. 

33 

Buckwheat . . . 

32 

Dust. 

35 

Coke 


Petroleum.... 

72 

Gas House . . . 

66 

Solvay Nut. . . 

55 


*Peabody Coal Company. 


Mr. J. A. Garcia of the Allen and Garcia Company, Chicago, has 
furnished the following results of actual tests on a large number of 
cars of coal loaded by the Dering Coal Company in 1907. The volume 
was calculated from measurements made on railroad carloads just 
after they left the mine tipple. The results are shown in Table 22. 
The work was scattered over a period of several months and the data 
were collected by three different division engineers acting under defi¬ 
nite instructions from Mr. Garcia. 


Table 22 

Weight per Cubic Foot of Illinois and Indiana CoalI 


Company 

Dering Coal Co. 

Cu. Ft. 
per Tont 

Wt. per 
Cu. Ft. 

Kind and Size of Coal 

Specific 

Gravity 

Remarks 

West Frankfort, 

Franklin County, Ill. 

34.8 
34.3 
37.0 

40.8 
41.2 
40.0 

57.4 
58.3 
54.1 
48.9 

48.5 
50.0 

Vein 6 

Mine-run 

Mine-run 

IK in- (round) Screenings 
IK in. to 3 in. Nut 

3 in. to 6 in. Egg 

6 in. Lump 

1.310 


Montgomery County, 
Ind., Vein 6. 

37.5 

38.1 

40.5 

38.6 
41.8 

42.1 

40.1 

53.2 

52.5 

49.4 

51.8 

47.8 

47.5 

49.8 

Vein 6 

Mine-run 

K in. bar (Screenings) 

6 in. (round) Screenings 
IK-3 in. Nut 

6 in. Lump 

IK in. Lump 

K in. (bar) 

1.339 




tEstimates of Mr. .1. A. Garcia. 
+2000 pounds 
























































BITUMINOUS COAL STORAGE PRACTICE 


147 


Table 22 —Continued 


Company 

Dering Coal Co. 

Cu. Ft. 
per Ton* 

Wt. per 
Cu. Ft. 

Kind and Size of Coal 

Specific 

Gravity 

Remarks 

Vermilion County, Ill. 

40.5 

45.2 

45.1 

50.2 

47.8 

43.8 

49.3 
44.1 

44.3 

39.8 

41.8 
45.6 

Vein 6 

Mine-run 

IK in. (bar) Screenings 

K in. (round) Screenings 
7 A~ 2 in. Nut 

2 in. (round) Lump 

1 K in. (bar) Lump 

1.305 


Vermilion County, Ind. 

36.7 

40.0 

54.4 

49.0 

Vein 3 

Mine-run 

1M in. (bar) Lump 

1.372 


Vermilion County, Ind. 

38.1 

40.8 

45.0 

42.6 

43.5 

52.5 

49.0 

44.4 

46.9 

45.9 

Vein 4 

Mine-run 

IK in. (bar) Screenings 
2K to 4 in. Egg 

4 in. Lump 

IK in. (bar) Lump 

1.241 


Vermilion County, Ind. 
and 

Sullivan County, Ind. 

37.2 

39.3 

38.3 
40.6 
39.9 

53.7 

50.9 

52.2 

49.2 
50.0 

Vein 5 

Mine-run 

Mine-run 

IK in. (bar) Screenings 

IK in. (bar) Lump 

IK in. (bar) Lump 

1.368 


Sullivan County, Ind. 

40.7 

38.3 
41.0 

37.7 

42.8 

42.8 

41.3 

45.3 
40.1 

42.3 

38.8 

42.8 

38.4 

42.5 

49.1 

52.2 

48.7 
52.9 

46.7 

46.7 

48.3 

44.1 

49.8 

47.2 
51.5 
46.7 
52.0 
47.0 

Vein 6 

1 K in. (bar) Screenings 

IK in. (bar) Screenings 
\K in. (round) Screenings 
1 in. (round) Screenings 
^K-2K in. Nut 

1-2M in. Nut 

2)^-4 in. Egg 

1^2-4 in. Egg 

21^-4 in. Egg 

IK in. (bar) Lump 

4 in. Lump 

4 in. Lump 

4 in. Lump 
\K in. Lump 




*2000 pounds. 


Tables 23 and 24 give other results for bituminous coal and Table 
25 gives results for anthracite coal. 


Table 23 


Space Occupied by Bituminous Coal in Cubic Feet per Ton! 


Kinds 

Cubic Feet 
Per Ton| 


36.65 
33.55 
40.15 
34.00 

fMines and Minerals, Nov., 1907. 

J2000 pounds. 

41.50 
42.30 









































148 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Table 24 

Space Occupied by Bituminous Coal in Cubic Feet per Ton* 


Kind 

Cubic Feet per Tout 

Kind 

Cubic Feet per Ton f 

Pittsburgh 

48 2 

Cumberland, Max. 

42.3 

Erie 

4b 6 

Cumberland. Min. 

41.2 

Hocking Valley 

45.4 

Blossburg, Pa. 

42.2 

Ohio Cannel 

45.5 

Clover Hill. Va. 

49.0 

Indiana Block 

51.1 

Richmond, Va. (Midlothian) 

41.0 

1 llinois 

47 4 

Cannelton, Ind. 

47.0 

Pi 1 Is. ’Hill 

47.1 

Pictou, N. S. 

45.0 



Sydney, Cape Breton 

47.0 


*'! iaut\vi:;c’s Engineer's Pocket Book. 
f2240 pounds. 

Table 25 

Space Occupied by Anthracite Coal in Cubic Feet per TonJ 


Kinds 

Cubic Feet per Ton^I 

Broken 

Egg 

Stove 

Chestnut 

Pea 

Lackawanna. 

Garfield Red Ash. 

Lykens Valley. 

Shamokin. 

Plymouth Red Ash . 

Wilkes-Barre. 

Lehigh. 

Lorberry. 

Scranton . 

Pittston. 

37.10 

37.30 

37.55 
38.05 

34.90 
34.95 

33.30 

34.65 
35.35 
35.45 

_ 

36.65 

36.95 

37.25 
37.70 
34.85 

34.35 
33.80 

34.20 

35.20 

34.95 

. 

34.90 

36.35 

37.55 
37.25 

34.75 

33.75 

33.55 
33.80 
34.60 

34.35 

34.35 

36.35 
37.25 
37.25 

34.70 
34.00 

32.55 

33.55 
33.30 

33.70 

37.25 

37.50 

38.50 

38.50 
36.90 
36.90 
33.05 
35.20 

34.95 

35.50 


i Mines and Minerals. 
^!2000 pounds. 


The following' formulas from which Table 26 was calculated are 
given in General Catalog 18 of the Gifford-Wood Company of New 
York (See Fig. 75). 



Flo. 75. Dimensions for Determining Volume and Weight of Coal Piles 


























































BITUMINOUS COAL STORAGE PRACTICE 


149 


Formulas 

For Bituminous Coal: 

Vol. of each conical end — 0.045815D 3 ; vol. of cone = 0.09163I) ;} . 

Vol. per foot of straight portion = 0.175D 2 . 

For Anthracite Coal: 

Vol. of each conical end = 0.0327D3; vol. of cone = 0.0654D 3 . 

Vol. per foot of straight portion = 0.125D-. 

Tons = Vol. in cu. ft. _i_ cu. ft. per ton, from table below. 40 cu. 
ft. per ton was used in calculating the following table. 


Table 26 

Volume and Tonnage of Bituminous Coal" Piles 



Vol. in Cubic Feet 

Short Tons 

D 

Feet 

Conical 

Per Ft. of 

Conical 

Per Ft. of 

Ends, 

Straight 

Ends, 

Straight 


Each 

Portion 

Each 

Portion 

10 

45.82 

17.50 

1.15 

0.44 

11 

60.90 

21.20 

1.52 

0.53 

12 

79.00 

25.20 

1.97 

0.63 

13 

100.50 

29.55 

2.51 

0.74 

14 

125.75 

34.30 

3.14 

0.86 

15 

154.30 

39.40 

3.86 

0.98 

16 

187.30 

44.80 

4.68 

1.12 

17 

225.00 

50.60 

5.63 

1.26 

18 

267.00 

56.70 

6.67 

1.42 

19 

314.00 

63.20 

7.85 

1.58 

20 

402.50 

70.00 

10.05 

1.75 

25 

715.00 

109.30 

17.88 

2.74 

30 

1236.00 

157.50 

30.85 

3.94 

35 

1965.00 

214.50 

49.10 

5.36 

40 

2930.00 

280.00 

73.20 

6.99 

45 

4170.00 

354.50 

104.10 

8.86 

50 

5720.00 

437.50 

143.00 

10.93 

55 

7620.00 

529.00 

190.50 

13.22 

60 

9900.00 

630.00 

247.50 

15.76 

65 

12600.00 

738.00 

315.00 

18.43 

70 

15700.00 

857.00 

392.00 

21.40 

75 

19320.00 

984.50 

483.00 

24.60 

80 

23450.00 

1120.00 

586.00 

28.00 

85 

28100.00 

1265.00 

702.50 

31.60 

90 

33400.00 

1420.00 

835.00 

35.50 

95 

39250.00 

1580.00 

980.00 

39.50 

100 

45815.00 

1750.00 

1145.00 

43.75 





















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Bulletin No. 1 . Tests of Reinforced Concrete Beams, by Arthur N. Talbot. 
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Bulletin No. 2. Tests of High-Speed Tool Steels on Cast Iron, by L. P. 
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available. 

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Arthur N. Talbot. 1907. None available. 


151 



152 


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Bulletin No. 16. A Study of Roof Trusses, by N. Clifford Ricker. 1907. 
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Bulletin No. 32. The Occluded Gases in Coal, by S. W. Parr and Perry 
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1 53 


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Beams, by N. Clifford Ricker. 1909. None available. 

Bulletin No. 36. The Thermal Conductivity of Fire-Clay at High Temper¬ 
atures, by J. K. Clement and W. L. Egy. 1909. Twenty cents. 

Bulletin No. 37. Unit Coal and the Composition of Coal Ash, by S. W. Parr 
and W. F. Wheeler. 1909. None available. 

Bulletin No. 38. The Weathering of Coal, by S. W. Parr and W. F. Wheeler. 
1909. Twenty-five cents. 

*Bulletin No. 39. Tests of Washed Grades of Illinois Coal, by C. S. McGovney. 
1909. Seventy-five cents. 

Bulletin No. 40. A Study in Heat Transmission, by J. K. Clement and C. M. 
Garland. 1909. Ten cents. 

Bulletin No. 41. Tests of Timber Beams, by Arthur N. Talbot. 1909. Thirty- 
five cents. 

*Bulletin No. 42. The Effect of Keyways on the Strength of Shafts, by Her¬ 
bert F. Moore. 1909. Ten cents. 

Bulletin No. 43. Freight Train Resistance, by Edward C. Schmidt. 1910. 
Seventy-five cents. 

Bulletin No. 44. An Investigation of Built-up Columns under Load, by 
Arthur N. Talbot and Herbert F. Moore. 1910. Thirty-five cents. 

* Bulletin No. 45. The Strength of Oxyacetylene Welds in Steel, by Herbert 
L. Whittemore. 1910. Thirty-five cents. 

Bulletin No. 46. The Spontaneous Combustion of Coal, by S. W. Parr and 
F. W. Kressman. 1910. Forty-five cents. 

*Bulletin No. 47. Magnetic Properties of Heusler Alloys, by Edward B. 
Stephenson. 1910. Twenty-five cents. 

* Bulletin No. 48. Resistance to Flow through Locomotive Water Columns, by 
Arthur N. Talbot and Melvin L. Enger. 1911. Forty cents. 

* Bulletin No. 49. Tests of Nickel-Steel Riveted Joints, by Arthur N. Talbot 
and Herbert F. Moore. 1911. Thirty cents. 

* Bulletin No. 50. Tests of a Suction Gas Producer, by C. M. Garland and 
A. P. Kratz. 1911. Fifty cents. 

Bulletin No. 51. Street Lighting, by J. M. Bryant and H. G. Hake. 1911. 
Thirty-five cents. 

* Bulletin No. 52. An Investigation of the Strength of Rolled Zinc, by Herbert 
F. Moore. 1911. Fifteen cents. 

* Bulletin No. 53. Inductance of Coils, by Morgan Brooks and H. M. Turner. 
1912. Forty cents. 

Bulletin No. 54. Mechanical Stresses in Transmission Lines, by A. Guell. 
1912. Twenty cents. 

* Bulletin No. 55. Starting Currents of Transformers, with Special Reference 
to Transformers with Silicon Steel Cores, by Trygve D. Yensen. 1912. Twenty 
cents. 


*A limited number of copies of bulletins starred are available for free distribution. 



154 


PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 


*Bulletin No. 56. Tests of Columns: An Investigation of the Value of Con¬ 
crete as Reinforcement for Structural Steel Columns, by Arthur N. Talbot and 
Arthur R. Lord. 1912. Twenty-five cents. 

*Bulletin No. 57. Superheated Steam in Locomotive Service. A Review of 
Publication No. 127 of the Carnegie Institution of Washington, by W. F. M 
Goss. 1912. Forty cents. 

*Bulletin No. 58. A New Analysis of the Cylinder Performance of Reciprocat¬ 
ing Engines, by J. Paul Clayton. 1912. Sixty cents. 

*Bulletin No. 59. The Effect of Cold Weather upon Train Resistance and 
Tonnage Rating, by Edward C. Schmidt and F. W. Marquis. 1912. Twenty cents. 

Bulletin No. 60. The Coking of Coal at Low Temperature, with a Preliminary 
Study of the By-Products, by S. W. Parr and H. L. Olin. 1912. Twenty-five cents. 

* Bulletin No. 61. Characteristics and Limitation of the Series Transformer, 
by A. R. Anderson and H. R. Woodrow. 1912. Twenty-five cents. 

Bulletin No. 62. The Electron Theory of Magnetism, by Elmer H. Williams. 

1912. Thirty-five cents. 

Bulletin No. 63. Entropy-Temperature and Transmission Diagrams for Air, 
by C. R. Richards. 1913. Twenty-five cents. 

*Bulletin No. 64. Tests of Reinforced Concrete Buildings under Load, by 
Arthur N. Talbot and Willis A. Slater. 1913. Fifty cents. 

*Bulletin No. 65. The Steam Consumption of Locomotive Engines from the 
Indicator Diagrams, by J. Paul Clayton. 1913. Forty cents. 

Bulletin No. 66. The Properties of Saturated and Superheated Ammonia 
Vapor, by G. A. Goodenough and William Earl Mosher. 1913. Fifty cents. 

Bulletin No. 67. Reinforced Concrete Wall Footings and Column Footings, 
by Arthur N. Talbot. 1913. None available. 

Bulletin No. 68. The Strength of I-Beams in Flexure, by Herbert F. Moore. 

1913. Twenty cents. 

Bulletin No. 69. Coal Washing in Illinois, by F. C. Lincoln. 1913. Fifty 
cents. 

Bulletin No. 70. The Mortar-Making Qualities of Illinois Sands, by C. C. 
Wiley. 1913. Twenty cents. 

Bulletin No. 71. Tests of Bond between Concrete and Steel, by Duff A. 
Abrams. 1913. One dollar. 

* Bulletin No. 72. Magnetic and Other Properties of Electrolytic Iron Melted 
in Vacuo, by Trygve D. Yensen. 1914. Forty cents. 

Bulletin No. 73. Acoustics of Auditoriums, by F. R. Watson. 1914. Twenty 
cents. 

*Bulletin No. 74. The Tractive Resistance of a 28-Ton Electric Car, by Harold 
H. Dunn. 1914. Twenty-five cents. 

Bulletin No. 75. Thermal Properties of Steam, by G. A. Goodenough. 1914. 
Thirty-five cents. 


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PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 


155 


Bulletin No. 76. The Analysis of Coal with Phenol as a Solvent, by S. W. 
Parr and H. F. Hadley. 1914. Twenty-five cents. 

* Bulletin No. 77. The Effect of Boron upon the Magnetic and Other Prop¬ 
erties of Electrolytic Iron Melted in Vacuo, by Trygve D. Yensen. 1915. Ten 
cents. 

Bulletin No. 78. A Study of Boiler Losses, by A. P. Kratz. 1915. Thirty - 
five cents. 

*Bulletin No. 79. The Coking of Coal at Low Temperatures, with Special Ref¬ 
erence to the Properties and Composition of the Products, by S. W. Parr and 
H. L. Olin. 1915. Twenty-five cents. 

Bulletin No. 80. Wind Stresses in the Steel Frames of Office Buildings, by 
W. M. Wilson and G. A. Maney. 1915. Fifty cents. 

Bulletin No. 81. Influence of Temperature on the Strength of Concrete, by 
A. B. McDaniel. 1915. Fifteen cents. 

Bulletin No. 82. Laboratory Tests of a Consolidation Locomotive, by E. C. 
Schmidt, J. M. Snodgrass, and R. B. Keller. 1915. Sixty-five cents. 

*Bulletin No. 83. Magnetic and Other Properties of Iron-Silicon Alloys, 
Melted in Vacuo, by Trygve D. Yensen. 1915. Thirty-five cents. 

Bulletin No. 84. Tests of Reinforced Concrete Flat Slab Structures, by 
Arthur N. Talbot and W. A. Slater. 1916. Sixty-five cents. 

*Bulletin No. 85. The Strength and Stiffness of Steel under Biaxial Loading, 
by A. J. Becker. 1916. Thirty-five cents. 

Bulletin No. 86. The Strength of I-Beams and Girders, by Herbert F. Moore 
and W. M. Wilson. 1916. Thirty cents. 

* Bulletin No. 87. Correction of Echoes in the Auditorium, University of Illi¬ 
nois, by F. R. Watson and J. M. White. 1916. Fifteen cents. 

Bulletin No. 88. Dry Preparation of Bituminous Coal at Illinois Mines, by 
E. A. Holbrook. 1916. Seventy cents. 

Bulletin No. 89. Specific Gravity Studies of Illinois Coal, by Merle L. Nebel. 
1916. Thirty cents. 

Bulletin No. 90. Some Graphical Solutions of Electric Railway Problems, by 
A. M. Buck. 1916. Twenty cents. 

Bulletin No. 91. Subsidence Resulting from Mining, by L. E. Young and 
H. H. Stoek. 1916. None available. 

*Bulletin No. 92. The Tractive Resistance on Curves of a 28-Ton Electric 
Car, by E. C. Schmidt and H. H. Dunn. 1916. Twenty-five cents. 

Bulletin No. 93. A Preliminary Study of the Alloys of Chromium, Copper, 
and Nickel, by D. F. McFarland and 0. E. Harder. 1916. Thirty cents. 

*Bulletin No. 94. The Embrittling Action of Sodium Hydroxide on Soft Steel, 
by S. W. Parr. 1917. Thirty cents. 

*Bulletin No. 95. Magnetic and Other Properties of Iron-Aluminum Alloys 
Melted in Vacuo, by T. D. Yensen and W. A. Gatward. 1917. Twenty-five cents. 


*A limited number of copies of bulletins starred are available for free distribution. 



156 


PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 


* Bulletin No. 96. The Effect of Mouthpieces on the Flow of Water through 
a Submerged Short Pipe, by Fred B Seely. 1917. Twenty-five cents. 

* Bulletin No. 97. Effects of Storage upon the Properties of Coal, by S. W. 
Parr. 1917. Twenty cents. 

* Bulletin No. 98. Tests of Oxyacetylene Welded Joints in Steel Plates, by 
Herbert F. Moore. 1917. Ten cents. 

Circular No. 4. The Economical Purchase and Use of Coal for Heating 
Homes, with Special Reference to Conditions in Illinois. 1917. Ten cents. 

* Bulletin No. 99. The Collapse of Short Thin Tubes, by A. P. Carman, 1917. 
Twenty cents. 

*Circular No. 5. The Utilization of Pyrite Occurring in Illinois Bituminous 
Coal, by E. A. Holbrook. 1917. Twenty cents. 

*Bulletin No. 100. Percentage of Extraction of Bituminous Coal with Special 
Reference to Illinois Conditions, by C. M. Young. 1917. 

*Bulletin No. 101. Comparative Tests of Six Sizes of Illinois Coal on a Mi¬ 
kado Locomotive, by E. C. Schmidt, J. M. Snodgrass, and O. S. Beyer, Jr. 1917. 
Fifty cents. 

*Bullctin No. 102. A Study of the Heat Transmission of Building Materials, 
by A. C. Willard and L. C. Lichty. 1917. Twenty-five cents. 

*Bulletin No. 103. An Investigation of Twist Drills, by B. Benedict and W. 
P. Lukens. 1917. Sixty cents. 

* Bulletin No. 104. Tests to Determine the Rigidity of Riveted Joints of Steel 
Structures, by W. M. Wilson and H. F. Moore. 1917. Twenty-five cents. 

Circular No. 6. The Storage of Bituminous Coal, by H. H. Stoek. 1918. 
Forty cents. 

Circular No. 7. Fuel Economy in the Operation of Hand Fired Power 
Plants. 1918. Tioenty cents. 

*Bulletin No. 105. Hydraulic Experiments with Valves, Orifices, Hose, Nozzles, 
and Orifice Buckets, by Arthur N. Talbot, Fred B Seely, Virgil R. Fleming, and 
Melvin L. Enger. 1918. Thirty-five cents. 

*Bulletin No. 106. Test of a Flat Slab Floor of the Western Newspaper Union 
Building, by Arthur N. Talbot and Harrison F. Gonnennan. 1918. Twenty cents. 

Circular No. 8. The Economical Use of Coal in Railway Locomotives. 1918. 
Twenty cents. 

*Bulletin No. 107. Analysis and Tests of Rigidly Connected Reinforced Con¬ 
crete Frames, by Mikishi Abe. 1918. Fifty cents. 

* Bulletin No. 108. Analysis of Statically Indeterminate Structures by the 
Slope Deflection Method, by W. M. Wilson, F. E. Richart, and Camillo Weiss. 
1918. One dollar. 

*Bulletin No. 109. The Pipe Orifice as a Means of Measuring Flow of Water 
through a Pipe, by R. E. Davis and H. H. Jordan, 1918. Twenty-five cents. 

*Bulletin No. 110. Passenger Train Resistance, by E. C. Schmidt and H. H. 
Dunn. 1918. Twenty cents. 


*A limited number of copies of bulletins starred are available for free distribution. 



PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 


157 


* Bulletin No. 111. A Study of the Forms in which Sulphur Occurs in Coal, by 
A. R. Powell with S. W. Parr. 1919. Thirty cents. 

* Bulletin No. 112. Report of Progress in Warm-Air Furnace Research, by 
A. C. Willard. 1919. Thirty-five cents. 

*Bulletin No. 113. Panel System of Coal Mining. A Graphical Study of Per¬ 
centage of Extraction, by C. M. Young. 1919. 

*Bulletin No. 114. Corona Discharge, by Earle H. Warner with Jakob Kunz. 
1919. Seventy-five cents. 

*Bulletin No. 115. The Relation between the Elastic Strengths of Steel in 
Tension, Compression, and Shear, by F. B Seely and W. J. Putnam. 1920. Twenty 
cents. 

* Bulletin No. 116. Bituminous Coal Storage Practice, by H. II. Stoek, C. W. 
Hippard, and W. D. Langtry. 1920. Ninety cents. 


*A limited number of copies of bulletins starred are available for free distribution. 







































































































































































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THE UNIVERSITY OF ILLINOIS 
THE STATE UNIVERSITY 
Urbana 

Edmund J. James, Ph. D., LL. D., President 


THE UNIVERSITY INCLUDES THE FOLLOWING DEPARTMENTS 
The Graduate School 

The College of Liberal Arts and Sciences (Ancient and Modem Languages and 
Literatures; History, Economics, Political Science, Sociology; Philosophy, 
Psychology, Education; Mathematics; Astronomy; Geology; Physics; Chem¬ 
istry; Botany; Zoology, Entomology; Physiology; Art and Design) 

The College of Commerce and Business Administration (General Business, Bank¬ 
ing, Insurance, Accountancy, Railway Administration, Foreign Commerce; 
Courses for Commercial Teachers and Commercial and Civic Secretaries) 
The College of Engineering (Architecture; Architectural, Ceramic, Civil, Electrical, 
Mechanical, Mining, Municipal and Sanitary, and Railway Engineering; 
General Engineering Physics) 

The College of Agriculture (Agronomy; Animal Husbandry; Dairy Husbandry; 
Horticulture and Landscape Gardening; Agricultural Extension; Teachers’ 
Course; Home Economics) 

The College of Law (Three-year and four-year curriculums based on two years and 
one year of college work respectively.) 

The College of Education 
The Curriculum in Journalism 

The Curriculums in Chemistry and Chemical Engineering 
The School of Railway Engineering and Administration 
The School of Music (four-year curriculum) 

The Library School (two-year curriculum for college graduates) 

The College of Medicine (in Chicago) 

The College of Dentistry (in Chicago) 

The School of Pharmacy (in Chicago, Ph. G. and Ph. C. curriculums) 

The Summer Session (eight weeks) 

Experiment Stations and Scientific Bureau: U. S. Agricultural Experiment Sta¬ 
tion; Engineering Experiment Station; State Laboratory of Natural History; 
State Entomologist’s Office; Biological Experiment Station on Illinois River; 
State Water Survey; State Geological Survey; U. S. Bureau of Mines Experi¬ 
ment Station. 

The library collections contain (October 1, 1919) 443,614 volumes and 53,037 
pamphlets. 

For catalogs and information address 

THE REGISTRAR 

Urbana, Illinois 





